Waterproof roof cargo bags add flexible storage without a hard-shell carrier, but capacity, attachment method, and rain protection vary across models. My best overall pick is the 21-cubic-foot 840D heavy-duty bag, which pairs a useful family-trip capacity with a stated heavy-duty fabric and broad vehicle fit. For more room, the Mockins 30-cubic-foot bag stands out; for a smaller load, the 15-cubic-foot 840D bag avoids carrying more bulk than you need. The main tradeoff is between usable capacity and easier handling, with rack compatibility and seam protection also affecting fit and weather readiness. Read on for the full comparison, buying advice, and a pick for different travel needs.
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Key Takeaways
- The 21-cubic-foot 840D bag is my best overall choice: it balances mid-to-large storage capacity with a specific heavy-duty fabric claim, while the 15-cubic-foot version is a better match for lighter loads.
- The Mockins 30- and 40-cubic-foot bags serve different jobs: the 30-cubic-foot model offers a substantial capacity step up, while the 40-cubic-foot XXL option is for buyers with unusually large loads and enough roof space.
- Capacity alone does not establish waterproof performance: the product names cite waterproofing, but buyers should verify seam construction, closure coverage, and care instructions before packing items that cannot get wet.
- Attachment details separate otherwise similar bags: the FIVKLEMNZ listing calls out reinforced straps and accessories, while the TANX and 21-cubic-foot listings specifically mention a lock or an anti-slip mat and hooks.
- Aerodynamic shape is a distinct priority, not a universal winner: Sailnovo calls out an aerodynamic design, which may appeal to drivers focused on profile, while buyers prioritizing space may prefer a larger listed capacity.
| waterproof roofcargo bag | Material | Dimensions | Capacity | Weight |
|---|---|---|---|---|
| Car Rooftop Cargo Carrier Bag | 840D abrasion-resistant PVC fabric | 52 x 40 x 18 inches | 21 cubic feet | 4.24 kg |
| Asinking Car Rooftop Cargo Car | 900D double-coated abrasion-resistant PVC-laminated tarpaulin | 40 x 52 inches | 20 cubic feet | — |
| Mockins 30 Cu Ft Navy Blue Hea | 840D vinyl | 60 x 43 x 20 inches | 30 cubic feet | — |
| Sailnovo Aerodynamic Rooftop C | Military-grade fabric with PVC coating | 51 x 39 x 17 inches | 20 cubic feet | 8.6 lb |
| Car Rooftop Cargo Carrier Bag | 840D PVC fabric | 44 x 34 x 17 inches | 15 cubic feet | 8.8 lb |
| FIVKLEMNZ Car Rooftop Cargo Ca | 840D PVC | 46 x 34 x 17 inches | — | 6.6 pounds |
| Mockins 20 Cu Ft Yellow Heavy | All-weather vinyl | 50 x 36 x 19 inches | 20 cubic feet | — |
| 21 CuFt Waterproof Rooftop Car | 840D PVC tarpaulin | 52 x 40 x 18 inches | — | 5.56 kg |
| TANX Car Roof Bag | 500D PVC tarpaulin | 52 x 40 x 17 inches | 21 cubic feet | 4.25 kg |
| FIVKLEMNZ 30 Cubic Feet Waterp | 840D PVC | 60 x 43 x 20 inches | — | Approximately 12 pounds |
| Car Roof Rooftop Cargo Carrier | 840D weatherproof PVC fabric | — | 21 cubic feet | — |
| Mockins 40 CuFt XXL Car Roof B | 840D vinyl | 72 x 48 x 20 inches | 40 cubic feet | — |
| Car Roof Bag Waterproof Roofto | 700D PVC tarpaulin and grid material | 51 x 40 x 17 inches | 20 cubic feet | 8.6 lb (3.9 kg) |
More Details on Our Top Picks
Car Rooftop Cargo Carrier Bag, 21 Cubic Feet, Waterproof, Heavy Duty 840D Car Roof Bag for All Vehicles with/Without Racks
I’d put this 21-cubic-foot carrier first for buyers who want a roomy, weather-focused bag without jumping to an extra-large format. Its 840D PVC fabric, sealed seams, and zipper flaps make water protection a central part of the design, while the included straps and hooks support rack-free mounting as well as use with racks. Compared with the Asinking 20-cubic-foot bag, it offers a little more stated capacity and similarly emphasizes waterproofing, though Asinking lists a specific IPX66 rating and a two-year warranty. This bag’s main tradeoff is its broad 52-by-40-inch footprint: it can be cumbersome to store and needs careful tightening to limit movement on the roof. I’d choose it over the smaller 15-cubic-foot 840D model when luggage volume matters more than compact storage.
Pros:- Waterproof construction includes sealed seams and zipper flaps.
- 840D abrasion-resistant PVC is suited to repeated loading and travel.
- 21-cubic-foot capacity provides more room than the 15-cubic-foot 840D option.
- Straps and hooks support installation on vehicles with or without racks.
Cons:- The large footprint may be difficult to store when not in use.
- Loose or poorly adjusted straps can allow the bag to shift during travel.
Best for: Families or road-trippers who need around 21 cubic feet of weather-protected roof storage and want a setup that can work with or without roof racks.
Not ideal for: Drivers with limited roof space or little room to store a bulky bag between trips, and anyone unwilling to check strap tension before and during travel.
- Capacity:21 cubic feet
- Material:840D abrasion-resistant PVC fabric
- Water protection:Waterproof with sealed seams and zipper flaps
- Dimensions:52 x 40 x 18 inches
- Weight:4.24 kg
- Mounting:Rooftop; compatible with vehicles with or without racks
- Closure:Zipper
- Color:Black
Our verdict“Choose this for a strong balance of 21-cubic-foot capacity and stated waterproof construction, provided you have room to mount and store it.”
Asinking Car Rooftop Cargo Carrier Bag, 20 Cubic Feet, Waterproof, Universal Fit
The Asinking is my pick for buyers who want a clear water-resistance claim alongside a family-sized load area. Its IPX66 rating, reinforced seams, and double-coated 900D PVC-laminated tarpaulin give it a more explicit weather-protection pitch than the Sailnovo, whose description cautions that it is not fully waterproof. At 20 cubic feet, it gives up a little volume to the 21-cubic-foot carrier in this lineup, but includes a non-slip mat, door hooks, a combination lock, and a storage bag, plus a listed two-year warranty. The added security and mounting pieces are useful, though the product data warns that setup can be complex and installation needs care. I’d favor it over the 21-cubic-foot option when its stated rating and included kit matter more than that extra cubic foot.
Pros:- Lists an IPX66 water-resistance rating and reinforced seams.
- 900D double-coated PVC-laminated tarpaulin offers abrasion-resistant construction.
- Includes a non-slip mat, door hooks, combination lock, and storage bag.
- Two-year warranty is specified in the product data.
Cons:- Installation may take more care than a straightforward strap setup.
- The large soft bag can affect vehicle aerodynamics if not secured properly.
- Its 20-cubic-foot capacity is smaller than the 21-cubic-foot options here.
Best for: Family travelers who prioritize a stated water-resistance rating, want rack-free mounting options, and value a mat and lock in the included kit.
Not ideal for: First-time roof-bag users who want the simplest possible setup, or buyers who need more capacity than 20 cubic feet.
- Capacity:20 cubic feet
- Material:900D double-coated abrasion-resistant PVC-laminated tarpaulin
- Water resistance:IPX66 rating; reinforced seams
- Dimensions:40 x 52 inches
- Included components:Non-slip mat, door hooks, combination lock, storage bag, user manual
- Warranty:2 years
- Vehicle fit:Vehicles with or without roof racks
Our verdict“Pick the Asinking if documented water resistance and a well-equipped mounting kit matter more to you than maximum capacity or simplest setup.”
Mockins 30 Cu Ft Navy Blue Heavy-Duty Soft Shell Rooftop Cargo Carrier Bag
When the priority is carrying bulky gear rather than keeping the roof load compact, the Mockins 30 is the clear capacity pick. Its 30 cubic feet and 60-by-43-by-20-inch dimensions exceed the 20- and 21-cubic-foot bags here, creating room for larger family or outdoor-trip loads. The flexible 840D vinyl shell, reinforced seams, and included non-slip mat aim to protect belongings and help the bag stay in place; a lock and five-year limited warranty are also listed. That extra volume comes with a real compromise: soft construction is less suited to very heavy loads than a rigid carrier, and the larger bag calls for careful securing. Compared with the 21-cubic-foot 840D model, this is the better choice for sheer space, but it demands more attention to loading and fit.
Pros:- 30-cubic-foot capacity is the largest among these five products.
- 840D vinyl and reinforced seams are designed for durable, weather-resistant use.
- Includes straps, hooks, a non-slip mat, a lock, and a storage bag.
- Listed five-year limited warranty is longer than the Asinking’s two-year warranty.
Cons:- Soft-shell construction may not support very heavy loads as well as a rigid carrier.
- Large dimensions require ample roof space and careful strap adjustment.
- Installation may be challenging for drivers unfamiliar with roof bags.
Best for: Large families and campers who regularly carry bulky equipment and have enough roof area for a 60-inch-long carrier.
Not ideal for: Drivers hauling very heavy items, using a small roof, or seeking a compact bag that is quick to manage and store.
- Capacity:30 cubic feet
- Dimensions:60 x 43 x 20 inches
- Material:840D vinyl
- Water protection:Waterproof, with reinforced seams
- Color:Navy blue
- Warranty:5-year limited warranty
- Included accessories:Straps, hooks, non-slip mat, lock, storage bag
- Shell type:Soft shell
Our verdict“Choose the Mockins 30 when you need substantially more room than the 20- and 21-cubic-foot bags and can manage a large soft load.”
Sailnovo Aerodynamic Rooftop Cargo Carrier Bag, 20 Cubic Feet Waterproof
The Sailnovo is aimed at drivers who want a 20-cubic-foot bag with an aerodynamic shape intended to reduce wind drag and noise. Its 51-by-39-by-17-inch profile is lower than the 20-inch-tall Mockins 30, but it also carries less, making it a more restrained option for family luggage or camping gear. The military-grade fabric with PVC coating is described as waterproof, yet the product details also say it is not 100% waterproof and advise caution in extreme weather. That caveat matters for anyone carrying items that cannot get damp: the Asinking’s stated IPX66 rating is the clearer choice for water-focused buyers. Sailnovo includes straps, locks, and storage accessories, but first-time setup may take effort and the vehicle needs enough roof space.
Pros:- 20-cubic-foot volume suits family luggage and camping gear.
- Aerodynamic design is intended to reduce wind drag and noise.
- Lower 17-inch height than the 30-cubic-foot Mockins bag.
- Includes straps, locks, and storage accessories.
Cons:- Product details caution that it is not 100% waterproof.
- First-time installation may require extra effort.
- Needs sufficient roof space despite its lower profile.
Best for: Drivers carrying ordinary luggage who prefer a lower-profile 20-cubic-foot soft bag and are not relying on it to protect sensitive cargo in severe weather.
Not ideal for: Travelers who need the clearest waterproof claim for valuables or expect frequent exposure to extreme weather.
- Capacity:20 cubic feet
- Dimensions:51 x 39 x 17 inches
- Weight:8.6 lb
- Material:Military-grade fabric with PVC coating
- Water resistance:Described as waterproof; product details caution it is not 100% waterproof
- Shell type:Soft
- Mounting:Roof
- Included accessories:Straps, locks, and storage accessories
Our verdict“Choose Sailnovo for a lower-profile, aerodynamic 20-cubic-foot bag, but select a product with a clearer waterproof claim for weather-sensitive cargo.”
Car Rooftop Cargo Carrier Bag, 15 Cubic Feet Waterproof Heavy Duty 840D Car Roof Bag for All Vehicles with/Without Racks
This 15-cubic-foot bag suits buyers who want the 840D waterproof construction of the larger 21-cubic-foot model without taking on as much roof-bag volume. Its 44-by-34-by-17-inch dimensions are smaller than the 21-cubic-foot carrier’s 52-by-40-by-18-inch footprint, which can make it a better fit for shorter trips or vehicles with less roof area. Sealed seams and zippers, plus straps, hooks, and a lock, give it a useful weather-protection and mounting package. The compromise is straightforward: it holds less than the 20-cubic-foot Asinking and the 30-cubic-foot Mockins, so it is less suited to large family loads. At 8.8 pounds, it is also heavier than some buyers may prefer for frequent handling.
Pros:- 840D abrasion-resistant PVC fabric is built for repeated travel use.
- Waterproof design includes sealed seams and zippers.
- Smaller dimensions than the 21-cubic-foot 840D carrier.
- Includes straps, hooks, and a lock for mounting and added security.
Cons:- 15-cubic-foot capacity is limited beside the 20-, 21-, and 30-cubic-foot options.
- Listed weight of 8.8 pounds may be cumbersome during handling.
- Requires careful installation to reduce shifting on the roof.
Best for: Couples or small families who need weather-protected space for a few bags and prefer a smaller roof footprint than a 20- or 21-cubic-foot carrier.
Not ideal for: Large families, campers with bulky equipment, or travelers who need to move a high volume of luggage outside the cabin.
- Capacity:15 cubic feet
- Material:840D PVC fabric
- Water protection:Waterproof with sealed seams and zippers
- Dimensions:44 x 34 x 17 inches
- Weight:8.8 lb
- Mounting:Roof; compatible with vehicles with or without racks
- Color:Black
- Included accessories:Straps, hooks, and lock
Our verdict“Pick this compact 840D bag for moderate luggage loads and a smaller footprint, but step up to the 21-cubic-foot version for family-sized packing.”
FIVKLEMNZ Car Rooftop Cargo Carrier Waterproof Roof Bag with Reinforced Straps and Accessories
I’d choose this 15-cubic-foot FIVKLEMNZ when a trip needs more room than the cabin offers but doesn’t call for a full-size rooftop load. Its 840D PVC and welded seams are aimed at keeping weather out, while reinforced straps and included accessories support a more secure setup. At 46 x 34 x 17 inches, it takes up less roof area than the 20-cubic-foot Mockins bag or the 21-cubic-foot TANX, a practical difference for buyers carrying a few duffels rather than bulky camping gear. The tradeoff is capacity: families packing several suitcases may outgrow it quickly. It also needs careful installation, and its soft shell can be bulky to store between trips. I’d rank it as a compact, weather-focused option, not a substitute for the larger bags.
Pros:- 840D PVC construction and welded seams are designed to resist water intrusion.
- 15-cubic-foot capacity suits moderate loads without taking up as much roof area as larger bags.
- Reinforced straps and included accessories support secure attachment.
- Universal fit is specified for vehicles with or without roof racks.
Cons:- Smaller capacity may not fit multiple large suitcases or bulky camping equipment.
- The soft bag can be bulky to store when not in use.
- Installation needs care to keep the carrier secure during travel.
Best for: Couples or small families who need weather-resistant space for a few bags and want a smaller rooftop footprint.
Not ideal for: Large families or campers carrying bulky equipment who need the capacity of the 20- or 21-cubic-foot options.
- Material:840D PVC
- Dimensions:46 x 34 x 17 inches
- Volume:15 cubic feet
- Weight:6.6 pounds
- Color:Black
- Shell type:Soft
- Mounting:Roof
- Fit:Universal
Our verdict“Choose this FIVKLEMNZ for a compact, waterproof-oriented carrier when 15 cubic feet is enough for your trip.”
Mockins 20 Cu Ft Yellow Heavy Duty Soft-Shell Waterproof Rooftop Cargo Bag
The Mockins pairs 20 cubic feet of storage with a particularly complete setup kit: the listing includes a roof mat, straps, hooks, a lock, and a storage case. That bundle gives it an advantage over the 15-cubic-foot FIVKLEMNZ for buyers who need more room and want key mounting pieces supplied together. Its all-weather vinyl, welded seams, and waterproof zippers address the weak points where rain can reach soft luggage, though no soft carrier should be treated as immune to leaks in every installation or storm. The larger size is useful for family or camping loads, but a fully packed bag can add wind resistance and requires strap adjustment for the vehicle. I’d favor it over the 21-cubic-foot TANX when the included mat and accessories matter more than a small capacity gain.
Pros:- 20-cubic-foot capacity accommodates substantial travel or camping gear.
- Waterproof zippers and welded seams target common water-entry points.
- Includes a roof mat, straps, hooks, lock, and storage case.
- A five-year limited warranty is specified.
Cons:- The large loaded profile can increase aerodynamic drag.
- Straps may need adjustment to fit different vehicle layouts.
- The yellow color may not suit buyers who prefer a low-visibility carrier.
Best for: Road-tripping families who want a 20-cubic-foot carrier with a mat, mounting hardware, lock, and storage case included.
Not ideal for: Drivers with limited roof space or those seeking a compact bag that is easy to store and has minimal aerodynamic impact.
- Capacity:20 cubic feet
- Dimensions:50 x 36 x 19 inches
- Material:All-weather vinyl
- Included components:Cargo bag, roof mat, straps, hooks, lock, storage case
- Closure details:Waterproof zippers and welded seams
- Warranty:5-year limited warranty
- Shell type:Soft shell
Our verdict“Pick the Mockins if you want a roomy soft carrier and a bundled roof mat and mounting kit rather than the smaller FIVKLEMNZ.”
21 CuFt Waterproof Rooftop Cargo Bag with Straps, Hooks, and Anti-Slip Mat
This bag has the largest stated capacity among the 15-, 20-, and 21-cubic-foot options here: 21 cubic feet, backed by 840D PVC tarpaulin and heat-welded seams. That combination makes it a logical choice for buyers prioritizing room and weather-resistant construction over a smaller roof footprint. Compared with the 21-cubic-foot TANX, it lists the same capacity and adds an anti-slip mat, but the TANX is lighter at 4.25 kg versus this model’s 5.56 kg. Straps, hooks, and a security lock are included, though the buckle closure and multiple attachment pieces call for careful setup. Its black-and-orange color scheme is also less discreet than the all-black TANX. I’d choose it for a large load, but not if low weight or understated appearance matters most.
Pros:- 21-cubic-foot capacity is the largest listed among these five products.
- 840D PVC tarpaulin and heat-welded seams are designed for weather resistance.
- Includes straps, hooks, a security lock, and an anti-slip mat.
- Folds for storage when not in use.
Cons:- At 5.56 kg, it is heavier than the 21-cubic-foot TANX.
- Black-and-orange is the only listed color combination.
- Installation may be challenging for buyers unfamiliar with roof-bag straps and hooks.
Best for: Travelers packing bulky family or camping gear who want 21 cubic feet and an anti-slip mat in the kit.
Not ideal for: Drivers who prioritize a lighter carrier, a discreet all-black look, or especially simple installation.
- Material:840D PVC tarpaulin
- Dimensions:52 x 40 x 18 inches
- Volume:21 cubic feet
- Weight:5.56 kg
- Color:Black and orange
- Closure:Buckle
- Mounting:Roof
- Fit:Universal
Our verdict“Choose this model for its 21-cubic-foot capacity and included anti-slip mat, but select the lighter TANX if carrying weight is a priority.”
TANX Car Roof Bag – 21 Cubic Feet Waterproof Rooftop Cargo Carrier with Straps and Lock
The TANX offers 21 cubic feet in a listed weight of 4.25 kg, making it the lighter of the two 21-cubic-foot choices here. Its 500D PVC tarpaulin is a different construction from the 840D material on the other 21-cubic-foot bag; buyers should not read the lower denier figure alone as a full measure of real-world waterproof performance, but it is a clear material distinction. The package includes straps, hooks, a lock, and a storage bag, and the universal fit is described for vehicles with or without roof racks. Compared with the larger FIVKLEMNZ 30-cubic-foot carrier, TANX takes up less space and should suit moderate loads better, though it gives up nine cubic feet. As a soft-sided bag, it also lacks the fixed shape of a hard carrier and requires careful attachment.
Pros:- 21-cubic-foot capacity provides ample room for luggage and trip gear.
- Listed weight of 4.25 kg is lower than the other 21-cubic-foot bag in this group.
- Includes straps, hooks, a lock, and a storage bag.
- Universal fit is specified for vehicles with or without roof racks.
Cons:- Uses 500D PVC tarpaulin rather than the 840D PVC listed for the competing 21-cubic-foot model.
- Soft-sided construction is less rigid than a hard-shell carrier.
- Multiple attachment components need careful setup.
Best for: Drivers who need 21 cubic feet but want a lighter bag and a storage case for off-trip packing.
Not ideal for: Travelers seeking the highest listed material denier or enough room for especially bulky loads like those suited to the FIVKLEMNZ 30-cubic-foot bag.
- Material:500D PVC tarpaulin
- Capacity:21 cubic feet
- Dimensions:52 x 40 x 17 inches
- Weight:4.25 kg
- Color:Black
- Mounting:Roof
- Fit:Universal
- Included accessories:Straps, hooks, lock, storage bag
Our verdict“Choose the TANX if you want a lighter 21-cubic-foot soft bag with a storage case and can accept 500D construction.”
FIVKLEMNZ 30 Cubic Feet Waterproof Soft Car Roof Cargo Carrier
With 30 cubic feet and dimensions of 60 x 43 x 20 inches, this FIVKLEMNZ is the clear capacity leader among the five products in this batch. It suits trips where the 21-cubic-foot TANX would force a tighter pack, such as family travel with bulky soft gear. The 840D PVC, reinforced straps, door hooks, and anti-slip mat provide a substantial attachment and weather-resistance package, with compatibility listed for vehicles with or without roof racks. The tradeoff is scale: at about 12 pounds and substantially larger than the 15-cubic-foot FIVKLEMNZ, it takes more space to store and may need more careful strap adjustment in wind. The supplied information also notes concerns about long-term durability, so I’d avoid treating the waterproof claim as a reason to overpack or neglect setup.
Pros:- 30-cubic-foot volume offers the most capacity in this batch.
- 840D PVC construction is specified for waterproof use.
- Includes reinforced straps, door hooks, and an anti-slip mat.
- Compatibility is listed for vehicles with or without roof racks.
Cons:- Its large size makes the carrier bulky to store between trips.
- Windy conditions may call for careful strap adjustment during installation.
- Product information notes concerns about long-term durability.
Best for: Large families and campers who routinely carry bulky gear and need more rooftop capacity than a 21-cubic-foot bag provides.
Not ideal for: Occasional travelers with compact loads, limited storage space, or vehicles where a large roof bag would be difficult to secure.
- Material:840D PVC
- Volume:30 cubic feet
- Dimensions:60 x 43 x 20 inches
- Weight:Approximately 12 pounds
- Mounting:Strap
- Features:Waterproof, heavy-duty, reinforced straps, door hooks, anti-slip mat
- Compatibility:Vehicles with or without roof racks
Our verdict“Choose this FIVKLEMNZ when maximum soft-bag capacity matters more than compact storage and straightforward setup.”
Car Roof Rooftop Cargo Carrier Bag Waterproof Luggage Storage 21 Cubic Feet, Soft Shell Large Roof Top Cargo Bag for SUV and Pickup Trucks (Black Gray)
This bag offers a useful middle ground: its 21-cubic-foot capacity gives family luggage room without the footprint of the Mockins 40 CuFt XXL. The 840D weatherproof PVC is intended to resist water, dust, and snow, while the included non-slip mat and door hooks give buyers several of the pieces needed to secure it. A foldable soft shell also takes less storage space at home than a rigid carrier. The tradeoff is that capacity alone does not guarantee a stable fit: the bag needs careful placement and tightening, and its compatibility still depends on available roof dimensions. Compared with the 20-cubic-foot Car Roof Bag Waterproof Rooftop Cargo Carrier, this one adds a little space and a listed storage bag, but buyers may find its installation directions unclear.
Pros:- 21 cubic feet provides substantial added luggage space without the 40-cubic-foot bulk of the Mockins XXL.
- 840D weatherproof PVC is designed to resist water, dust, and snow.
- Includes a non-slip mat, door hooks, and combination lock.
- Foldable design and included storage bag simplify off-season storage.
Cons:- Careful securing is needed to reduce sliding or vibration while driving.
- Fit depends on the vehicle’s roof dimensions.
- Installation instructions may be unclear.
Best for: Drivers of SUVs, sedans, or hatchbacks who want roughly 21 cubic feet of soft-shell storage and included mounting accessories.
Not ideal for: Travelers carrying bulky moving loads who need the Mockins 40 CuFt XXL’s much larger capacity, or drivers whose roof dimensions do not suit a large soft bag.
- Capacity:21 cubic feet
- Material:840D weatherproof PVC fabric
- Shell type:Soft
- Mounting type:Roof
- Compatibility:Most cars, SUVs, trucks, sedans, hatchbacks, and wagons
- Included accessories:Storage bag, non-slip mat, door hooks, combination lock
Our verdict“Choose this for a flexible, mid-size storage boost with useful included accessories, provided you can check the roof fit and secure it carefully.”
Mockins 40 CuFt XXL Car Roof Bag 72″x48″x20″ Soft-Shell Waterproof Cargo Carrier
When the deciding factor is how much gear can leave the cabin, the 40-cubic-foot capacity sets this Mockins apart from the 20- and 21-cubic-foot bags in this roundup. Its 72-by-48-by-20-inch size is better suited to bulky trip loads or moving than to a modest luggage overflow, and the 840D vinyl construction is described as waterproof. Multiple attachment options plus a roof mat, straps, hooks, and lock provide a more complete setup than a bag with fewer listed accessories. That scale brings real compromises: it can be bulky to store, and a large soft load requires careful attachment to limit movement. Compared with the 21-cubic-foot Car Roof Rooftop Cargo Carrier, it offers nearly double the capacity, but is a less practical choice for buyers who value compact storage or carry only a few bags.
Pros:- 40 cubic feet accommodates substantially more cargo than the 20- and 21-cubic-foot options.
- Large stated dimensions suit bulky loads.
- 840D vinyl construction is described as waterproof.
- Includes straps, hooks, a roof mat, lock, and carry bag, plus multiple attachment options.
Cons:- XXL dimensions can make the bag bulky to store between trips.
- Requires careful securing to limit movement during travel.
Best for: Families packing for extended trips or people moving bulky belongings who have enough roof area for an XXL carrier.
Not ideal for: Occasional travelers with limited storage space or small loads; the 40-cubic-foot bag may be more carrier than they need.
- Capacity:40 cubic feet
- Dimensions:72 x 48 x 20 inches
- Material:840D vinyl
- Shell type:Soft shell
- Warranty:10 years
- Included components:Roof bag, straps, hooks, car roof mat, lock, carry bag
Our verdict“Pick the Mockins XXL when maximum soft-shell capacity matters more than easy storage or a compact roof load.”
Car Roof Bag Waterproof Rooftop Cargo Carrier 20 Cubic Feet
This 20-cubic-foot bag is the clearest fit for buyers who need a carrier that is listed for cars with or without roof racks. Its 51-by-40-by-17-inch dimensions and 8.6-pound listed weight offer a more defined size and carry weight than the 21-cubic-foot Car Roof Rooftop Cargo Carrier, which does not list dimensions or weight. The 700D PVC tarpaulin and grid material is described as waterproof and tearproof, and the package lists an anti-slip mat, security hooks, reinforced straps, and a combination lock. The tradeoff is that installation may take effort to secure properly, and its capacity is half that of the Mockins 40 CuFt XXL. I would favor this one for rack-free flexibility, not for moving a large volume of bulky cargo.
Pros:- Listed compatibility with cars both with and without roof racks.
- 20-cubic-foot capacity suits luggage overflow without the scale of the Mockins 40 CuFt XXL.
- 700D PVC tarpaulin and grid material are described as waterproof and tearproof.
- Includes anti-slip mats, security hooks, reinforced straps, and a combination lock.
Cons:- Securing the bag may require extra installation effort.
- 20 cubic feet is less suitable for bulky moving loads than the Mockins 40 CuFt XXL.
- Only black is listed as a color.
Best for: Drivers with cars that lack roof racks who want a defined-size, 20-cubic-foot soft cargo bag with listed anti-slip and security accessories.
Not ideal for: Travelers moving bulky loads who need more than 20 cubic feet, or anyone seeking a carrier that requires little setup.
- Capacity:20 cubic feet
- Dimensions:51 x 40 x 17 inches
- Weight:8.6 lb (3.9 kg)
- Material:700D PVC tarpaulin and grid material
- Mounting type:Roof
- Closure type:Zipper
- Compatibility:Cars with or without roof racks
- Additional features:Waterproof, tearproof, anti-slip mats, security hooks, combination lock
- Color:Black
Our verdict“Choose this for rack-free compatibility and a specified mid-size fit, but look to the Mockins XXL if cargo volume is your priority.”
How We Picked
I ranked these waterproof roof cargo bags by how clearly their stated features answer the practical questions buyers face: how much they can carry, how they attach, what weather protection is claimed, and whether the design suits a smaller or larger load. I gave more weight to useful, specific details—such as 840D fabric, reinforced straps, included accessories, an anti-slip mat, or a stated aerodynamic shape—than to broad claims alone. Because the product information supplied does not establish independent weather testing or construction details for every bag, I do not treat the word “waterproof” as proof that every seam and closure will keep water out.
The order favors balanced capacity and stated build details first, then separates options by clear use case. The 21-cubic-foot 840D bag leads as a practical middle ground; the 15-cubic-foot version favors lighter loads, while the 30- and 40-cubic-foot Mockins bags suit buyers who need more room. Products with named attachment or profile features earn a distinct place, but listings with fewer differentiating details rank lower because buyers have less information to judge fit and weather performance. I would still verify dimensions, vehicle compatibility, and included hardware before choosing any model.
| waterproof roofcargo bag | Mounting | Color |
|---|---|---|
| Car Rooftop Cargo Carrier Bag | Rooftop; compatible with vehicles with or without racks | Black |
| Asinking Car Rooftop Cargo Car | — | — |
| Mockins 30 Cu Ft Navy Blue Hea | — | Navy blue |
| Sailnovo Aerodynamic Rooftop C | Roof | — |
| Car Rooftop Cargo Carrier Bag | Roof; compatible with vehicles with or without racks | Black |
| FIVKLEMNZ Car Rooftop Cargo Ca | Roof | Black |
| Mockins 20 Cu Ft Yellow Heavy | — | — |
| 21 CuFt Waterproof Rooftop Car | Roof | Black and orange |
| TANX Car Roof Bag | Roof | Black |
| FIVKLEMNZ 30 Cubic Feet Waterp | Strap | — |
| Car Roof Rooftop Cargo Carrier | — | — |
| Mockins 40 CuFt XXL Car Roof B | — | — |
| Car Roof Bag Waterproof Roofto | — | Black |
Factors to Consider When Choosing Waterproof Roofcargo Bags
Capacity labels and “waterproof” claims are useful starting points, not a complete fit check. I would compare the bag with the gear you actually carry, your roof setup, and the way you plan to secure and maintain it. These broader checks can prevent the common mistake of buying by cubic feet alone.
Choose Capacity by the Shape of Your Load
A cubic-foot figure describes volume, not the size or shape of the opening, so bulky sleeping bags and long sports gear may not pack as neatly as clothing. The lineup spans 15, 20, 21, 30, and 40 cubic feet, making the difference between a compact trip load and a large family haul substantial. Before choosing, group your usual roof-bound items and compare their dimensions with the product’s listed dimensions, not just its capacity. An oversized bag can be harder to load evenly and may leave unused space that shifts in transit. If your gear varies from trip to trip, a mid-size option can be easier to manage than buying the largest bag available.
Check the Whole Water-Protection System
A waterproof label does not tell you how seams are treated, how the closure folds, or how water may pool on the bag. Ask for details on seams, zipper or flap coverage, and closure direction before relying on a soft carrier for sensitive items. Packing clothes inside separate dry bags adds a second layer of protection without requiring a different roof carrier. Keep electronics, documents, and medication in the cabin whenever possible. After a wet trip, dry the bag fully before storage; trapped moisture can create odor and damage even when the outer material is intact.
Match the Attachment Setup to Your Roof
“Fits all vehicles” is not a substitute for checking the exact attachment method against your car’s roof. Compare whether your vehicle has crossbars, side rails, or a bare roof, then confirm which straps, hooks, or protective pieces are included. A listed anti-slip mat or reinforced straps may help with setup, but the product details should still explain how each component is used. Do not assume accessories are interchangeable between carriers or that every roof surface can accept a strap routed through a door opening. Follow the vehicle and carrier instructions, and check that straps cannot interfere with doors, windows, or airbags.
Treat Fit and Load Limits as Separate Checks
A bag can fit the roof footprint and still exceed the vehicle’s permitted roof load once the carrier and luggage are counted. Check the owner’s manual for the roof’s dynamic load limit, then add the weight of the bag and all packed gear. Capacity is volume, not weight allowance; dense equipment can reach a load limit while leaving plenty of empty space. Measure the roof and compare it with the carrier’s dimensions so the bag does not obstruct visibility or extend into an unsafe position. Recheck the packed load after a short drive, following the carrier’s instructions.
Decide When a Larger Bag Is Worth the Extra Bulk
A larger carrier makes sense when you regularly move bulky family luggage or need to free cabin space, but it can be harder to lift, load, and store. The jump from a 21-cubic-foot bag to a 30- or 40-cubic-foot model is most useful when you can fill that capacity safely and secure it evenly. Occasional small loads may sit loosely in an oversized bag, increasing the challenge of keeping contents stable. If roof space, storage at home, or loading height is limited, a smaller bag may be the more practical choice. Pay more attention to construction and included fit hardware when frequent use makes repeated setup and packing part of the routine.
Plan for Care, Storage, and Road Conditions
Soft carriers need attention before and after a trip: inspect straps and closures, clear grit from fastening areas, and let the material dry before folding it away. A bag that suits a weekend drive may not be the best fit for frequent long-distance use if its instructions do not explain care or load security. Look for clear guidance on speed limits, strap checks, and storage, and follow the vehicle and carrier makers’ directions. Avoid placing sharp-edged gear directly against the fabric; use protective wrapping or a rigid inner container. If you expect exposed roof travel in heavy rain, confirm the specific weather limitations rather than treating a general waterproof claim as a guarantee.
Frequently Asked Questions
Is a 20- or 21-cubic-foot roof bag large enough for a family trip?
It can be enough for soft luggage and overflow items, but the capacity figure alone cannot confirm that your family’s gear will fit. Compare the bag’s dimensions with your packed items, especially strollers, coolers, or other rigid pieces that do not compress. The 20- and 21-cubic-foot options in this lineup are more moderate than the Mockins 30- and 40-cubic-foot bags. Also check your vehicle’s roof load limit, since a larger bag does not raise the permitted weight. Keep fragile or water-sensitive items protected inside the carrier.
Can I use a roof cargo bag on a car without roof racks?
Some listings describe fit for vehicles with or without racks, but that claim should be checked against the bag’s actual strap routing and your vehicle’s roof and door design. Confirm that the instructions permit your setup and that straps will not interfere with doors, windows, seals, or airbags. A bare-roof installation may need different positioning or protective material than a rack-mounted setup. Do not rely on a generic universal-fit phrase when the product page does not explain attachment. If the fit remains unclear, ask the maker before loading the bag.
Does a waterproof roof bag keep everything dry in heavy rain?
A waterproof claim does not by itself confirm that every seam, zipper, and closure will resist prolonged heavy rain or water driven by road speed. Look for construction details and stated weather limits, then pack valuables in separate waterproof liners as backup. Avoid letting water pool on the bag and check that its closure is positioned as directed. The product information in this roundup does not provide independent rain-test results for every model. For items that must stay dry, keep them in the cabin or use a second sealed container.
What should I check before choosing the 40-cubic-foot option?
First compare the bag’s stated dimensions with your roof footprint; a high capacity is only useful if the carrier sits securely and does not obstruct visibility. Then check the vehicle’s roof load limit, including the weight of the bag and its contents. A very large bag can be awkward to lift, fill evenly, and store between trips. It is a better match for frequent bulky loads than for occasional small luggage. Confirm the attachment hardware and weather-protection details, since capacity does not answer either question.
Should I choose an anti-slip mat or reinforced straps over more capacity?
Choose based on the problem you need to solve: a mat may help protect and stabilize the contact area, while reinforced straps speak to the attachment setup. Neither feature replaces checking vehicle compatibility, load limits, or the maker’s installation instructions. If your usual trips involve modest luggage, secure fit and manageable handling can matter more than moving from 21 to 30 cubic feet. If you routinely carry bulky gear, capacity may take priority, provided the roof and attachment system can handle the load. Compare what is actually included rather than assuming similar-looking bags share the same hardware.
Conclusion
My best overall recommendation is the 21-cubic-foot 840D bag: it combines a useful capacity with a specific heavy-duty fabric claim. For best value in practical sizing, I would start with the 15-cubic-foot 840D option if your loads are modest, rather than carrying excess bulk. The best premium-style capacity choice is the Mockins 40-cubic-foot XXL bag for buyers with large, frequent loads and suitable roof space; the 30-cubic-foot Mockins is a less extreme step up. For beginners, the FIVKLEMNZ listing with reinforced straps and accessories offers more setup detail to assess, though I would confirm exactly what is included. For specific needs, choose Sailnovo for its stated aerodynamic profile, TANX for its listed lock, or the 21-cubic-foot option with an anti-slip mat and hooks when those accessories fit your setup. Before buying, verify roof dimensions, load limits, attachment instructions, and the details behind the waterproof claim.
