Best 21 Cubic Feet Roof Cargo Boxes: 6 Spec-Based Picks

Quick picks

The best fit for you

• You need a waterproof bag without roof racks MeeFar 21 cu ft Waterproof Roof Bag It offers 100% waterproofing and works with or without roof racks.
• You want the lightest soft-shell option available Sailnovo 21 cu ft Soft Roof Bag It weighs only 8.16 pounds, making it the lightest choice listed.
• You drive a full-size SUV with roof racks Runave 70 in Hard Shell 21 cu ft Its 70-inch length and hard shell are built for larger vehicles.
• You need dual-side access for a hard box CNSLCJR 21 Cu Ft Hard Shell Dual-Side Opening Box It features dual-side opening and tool-free mounting for easy access.

Our 6 picks

1 Best overall

MeeFar 21 cu ft Waterproof Roof Bag

Best for: drivers needing a waterproof, rack-free roof bag

Size

21 Cubic Feet (what this guide is about)

Capacity

21 cu ft

Shell Type

Soft shell, 800D PVC tarpaulin

Water Resistance

100% waterproof

Security

Combination lock

Vehicle Compatibility

Vehicles with or without roof rack

View on Amazon: MeeFar 21 cu ft Waterproof Roof Bag Affiliate link

The MeeFar 21 cu ft Roof Bag is a soft-shell cargo carrier made from 800D PVC tarpaulin with waterproof zippers. It measures 47 x 35 x 22 inches and works with or without a roof rack. A combination lock adds security, and included door hooks replace interior straps. This bag suits drivers who want a lightweight, waterproof storage option for extra luggage.

Pros

• 100% waterproof 800D PVC tarpaulin material with waterproof zipper and zipper flap
• Combination lock included for added security
• Works with or without a roof rack
• Includes 4+2 free door hooks for safer installation
• Large 21 cu ft capacity fits 4-6 suitcases

Cons

• Soft-shell design offers less protection for items than a hard shell box
• No dual-side opening feature found on some hard shell models
• Heights vary across size options, so check dimensions for your vehicle

Good fit if

• You need a roof cargo carrier that works on a car without a roof rack
• You want a lightweight, waterproof bag for occasional trips
• You prefer a combination lock over a separate padlock

Skip if

• You want a hard shell box for better aerodynamics and security
• You need a carrier with dual-side opening access
• You plan to carry heavy or fragile items that require rigid protection

Verdict: MeeFar 21 cu ft Roof Bag is a practical soft-shell cargo carrier that offers 100% waterproofing, a combination lock, and compatibility with or without roof racks, making it a versatile choice for budget-conscious travelers.

2 Also great

Sailnovo 21 cu ft Soft Roof Bag

Best for: lightweight, waterproof soft-shell cargo on a budget

Size

21 Cubic Feet (what this guide is about)

Capacity

21 cubic feet

Shell Type

Soft Shell

Water Resistance

Waterproof

Installation

Tie-Down Strap

Dimensions

9.84 x 7.09 x 13.8 in

View on Amazon: Sailnovo 21 cu ft Soft Roof Bag Affiliate link

The Sailnovo 21 cu ft Soft Roof Bag is a waterproof soft-shell cargo carrier that installs with tie-down straps. It measures 9.84 x 7.09 x 13.8 inches and weighs 8.16 pounds. This bag suits you if you want a lightweight, collapsible option for occasional use without a permanent roof box.

Pros

• Waterproof construction protects your gear from rain
• Lightweight at 8.16 pounds for easy handling and storage
• Tie-down strap installation works with most vehicles without a rack
• Available in two sizes (21 and 15 cubic feet) to match your needs

Cons

• Soft shell offers less security and protection than hard-shell boxes
• No dual-side opening or locking mechanism listed
• Dimensions are compact (9.84 inches long) for a 21 cu ft capacity

Good fit if

• You want a budget-friendly, collapsible cargo carrier for occasional trips
• You need a waterproof bag that stores flat when not in use
• You have a vehicle without a roof rack and prefer strap mounting

Skip if

• You need a hard shell for better security and aerodynamics
• You plan to carry heavy or fragile items that require rigid protection
• You want a roof box with dual-side opening for easier access

Verdict: Sailnovo 21 cu ft Soft Roof Bag is a practical soft-shell option if you prioritize lightweight, waterproof storage and easy strap installation over the rigidity and security of a hard box.

3 Best budget

Rooftop Ranger 21 cu ft Soft Shell Cargo Carrier

Best for: budget-minded shoppers with or without roof racks

Size

21 Cubic Feet (what this guide is about)

Capacity

21 cu ft

Shell Type

Soft shell

Water Resistance

100% waterproof

Security

Security lock

Installation

Door hooks and straps

View on Amazon: Rooftop Ranger 21 cu ft Soft Shell Cargo Carrier Affiliate link

The Rooftop Ranger is a 21-cubic-foot soft shell cargo carrier that measures 54 x 42 x 17 inches and weighs 8.5 pounds. It is rated 100% waterproof and installs with door hooks and straps, so it works on vehicles with or without roof racks. The included security lock and non-slip mat make it a practical budget-oriented choice for occasional trips.

Pros

• 100% waterproof soft shell construction
• Installs with door hooks and straps on vehicles with or without roof racks
• Includes a security lock and non-slip mat
• Weighs only 8.5 pounds
• 21 cubic feet of capacity in a 54 x 42 x 17 in footprint

Cons

• Soft shell offers less protection than a hard shell box
• No dual-side opening or rigid shell structure listed
• Requires strapping and hooking to the vehicle each time

Good fit if

• You want a lightweight, low-cost soft shell carrier
• You have a vehicle without roof racks
• You need 21 cubic feet of weatherproof storage for occasional trips

Skip if

• You want a hard shell box with rigid protection
• You prefer a carrier with dual-side opening access
• You need a permanently mounted roof box

Verdict: Rooftop Ranger 21 cu ft Soft Shell Carrier is a practical budget pick for drivers who want 21 cubic feet of waterproof cargo space without needing roof racks.

4 Best premium

Runave 70 in Hard Shell 21 cu ft

Best for: full-size SUVs and pickup trucks with roof racks

Size

21 Cubic Feet (what this guide is about)

Capacity

21 Cubic Feet

Shell Type

ABS and PMMA

Opening

dual-side

Load Capacity

200 lbs

Water Resistance

waterproof

View on Amazon: Runave 70 in Hard Shell 21 cu ft Affiliate link

The Runave 70-inch hard-shell cargo box gives you 21 cubic feet of storage with a 200-pound load limit. It is made from ABS and PMMA materials, opens from both sides, and comes with two keys and straps for security. This box suits drivers of full-size SUVs, large crossovers, and pickup trucks who want a durable, aerodynamic carrier.

Pros

• Dual-side opening for easy access from either side of the vehicle
• Waterproof and UV-resistant ABS and PMMA hard shell
• Supports up to 200 lbs of cargo
• No additional tools required for installation
• Available in 8 color options

Cons

• Only 14.5 inches tall, limiting bulky items
• Compatibility limited to crossbars 17.3–35 inches wide and under 3 inches thick
• No built-in lighting or remote locking listed

Good fit if

• You drive a full-size SUV, large crossover, or pickup truck with a roof rack
• You want a hard-shell box that opens from both sides
• You need a waterproof carrier with UV protection

Skip if

• You have a smaller car or a vehicle without a roof rack
• You need a taller box for items over 14.5 inches high
• You prefer a soft-shell cargo bag for occasional use

Verdict: Runave 70 in Hard Shell 21 cu ft is a practical dual-side opening cargo box with a durable waterproof shell and a 200-pound capacity, best for full-size vehicles with a roof rack.

5 Also great

CNSLCJR 21 Cu Ft Hard Shell Dual-Side Opening Box

Best for: drivers wanting a secure, dual-side hard shell box

Size

21 Cubic Feet (what this guide is about)

Capacity

21 Cu Ft

Shell Type

ABS & PMMA

Opening

Dual side (passenger-side)

Load Capacity

150 lbs

Water Resistance

Protects from rain, dust, wind, UV

View on Amazon: CNSLCJR 21 Cu Ft Hard Shell Dual-Side Opening Box Affiliate link

This hard-shell cargo box from CNSLCJR offers 21 cubic feet of storage with dimensions of 72.83 x 34.25 x 14.76 inches and a 150-pound load capacity. Its dual-side opening (passenger-side) and tool-free installation make loading and mounting straightforward. It suits drivers who want a durable ABS & PMMA shell with a security lock that prevents key removal until all latches are closed.

Pros

• Dual-side opening (passenger-side) with support arms for easier loading
• Tool-free installation fits round, square, and most aerodynamic cross bars up to 3 inches wide
• Security lock system allows key removal only when all latches are fully closed
• Heavy-duty ABS & PMMA construction protects against rain, dust, wind, and UV
• Available in 20 variations including different sizes and colors

Cons

• At 38.9 pounds, it is heavier than many soft-shell cargo carriers
• No internal lights or remote locking features listed
• Requires verifying cross bar width and mounting distance before purchase

Good fit if

• You want a hard shell box with a 150-pound capacity and dual-side opening
• You prefer tool-free installation that works with various cross bar shapes
• You value a security lock that confirms all latches are closed before you can remove the key

Skip if

• You need a lighter cargo carrier under 30 pounds
• You want a box with built-in interior lights or a remote locking system
• You prefer a single-side opening design for easier access from one side only

Verdict: CNSLCJR 21 Cu Ft Hard Shell Dual-Side Opening Box is a practical hard-shell option with a 150-pound capacity, dual-side opening, and tool-free mounting, though its 38.9-pound weight and lack of interior lights may be considerations for some buyers.

6 Also great

Runave 72-inch Hard Shell Roof Box

Best for: full-size SUVs and pickup trucks needing dual-side access

Size

21 Cubic Feet (what this guide is about)

Capacity

21 Cubic Feet

Shell Type

ABS and PMMA

Opening

dual-side

Load Capacity

200 lbs

Water Resistance

waterproof

View on Amazon: Runave 72-inch Hard Shell Roof Box Affiliate link

The Runave 72-inch Hard Shell Roof Box offers 21 cubic feet of storage with a 200-pound load capacity. It is made from ABS and PMMA materials, is waterproof, and has a dual-side opening for easy access. This hard-shell box is designed for full-size SUVs, large crossovers, and pickup trucks with compatible roof racks.

Pros

• Dual-side opening for access from either side of the vehicle
• 200-pound load capacity and 21 cubic feet of storage
• Waterproof and UV-resistant ABS and PMMA construction
• Includes 2 keys and 2 straps for security
• Installation requires no additional tools

Cons

• Heavier than soft-shell cargo carriers
• Requires compatible crossbars with mounting width between 20.86 and 38.6 inches
• Not suitable for smaller vehicles due to 72.8-inch length

Good fit if

• You drive a full-size SUV, large crossover, or pickup truck
• You want a hard-shell box with dual-side opening for easy loading
• You need a waterproof and UV-resistant carrier for road trips

Skip if

• You have a small car or compact SUV
• You prefer a lightweight soft-shell cargo bag
• Your roof rack crossbars are thicker than 3 inches or have a mounting width outside 20.86 to 38.6 inches

Verdict: Runave 72-inch Hard Shell Roof Box provides solid 21-cubic-foot capacity with dual-side access and durable materials, making it a reliable choice for larger vehicles.

Specifications side by side

Is 21 Cubic Feet the Right Size for You?

Twenty-one cubic feet offers a middle ground for roof storage. It holds more than small bags but fits narrower vehicles better than 200-liter hard shells. You get enough room for weekend gear without drastically increasing drag or blocking rear visibility. Soft shell options like the Sailnovo weigh under nine pounds, while hard shells like the CNSLCJR add security but tip the scales at nearly 39 pounds. This capacity suits most standard SUVs and sedans with roof racks.

Worth it if

• You need extra space for family weekend trips without buying a large hard shell.
• You drive a mid-size SUV or sedan where larger boxes might overhang too much.
• You want a balance between cargo volume and vehicle aerodynamics.

Skip it if

• You only carry a few small items and prefer a compact soft bag.
• You regularly transport large outdoor gear like kayaks or long lumber.
• You have a vehicle with very low roof clearance and need minimal height.

How We Selected 21 Cubic Feet Boxes

We identified these cargo carriers by scanning Amazon listings for the specific 21 cubic feet capacity. We included only one size variant per product family to keep the comparison clear. All details come directly from the published specifications and feature lists on those listings. We do not handle the products ourselves. The data is strictly based on what the manufacturers state online. This ensures you see only the factual dimensions and materials provided by the sellers.

The products are ordered by availability first. We then sort by the listing's overall rating weighted by the number of ratings. Finally, we consider how many of our core criteria the specs meet. This method highlights the most relevant 21 cubic feet options for your vehicle. You can trust this ordering reflects current market data and verified customer feedback volume.

How to Choose the Right 21 Cu Ft Carrier

1. Check Shell Type First

   Decide between soft shells and hard shells based on your rack setup. Soft shells like the MeeFar 21 cu ft Roof Bag work without roof racks. They wrap around your roof. Hard shells like the Runave 70 in require existing crossbars. They mount securely to bars. Soft shells are lighter and flexible. Hard shells offer more rigidity. Choose soft shells for versatility. Pick hard shells for durability. Your current vehicle equipment dictates this choice.

2. Verify Length Compatibility

   Measure your roof space before buying. The Runave 70 in Hard Shell measures 70 inches long. The CNSLCJR model extends to 73.4 inches. These lengths may not fit smaller sedans. Soft shells are more forgiving. The Sailnovo Soft Roof Bag folds for storage. The Rooftop Ranger measures 54 inches long. Check your vehicle’s roof dimensions. Ensure the carrier does not overhang excessively. Proper length prevents aerodynamic issues and safety hazards.

3. Assess Weight Limits

   Know your roof’s dynamic load limit. The Runave 70 in supports 200 pounds. The CNSLCJR box holds 150 pounds. Soft bags generally have lower limits. The MeeFar bag is a practical choice for moderate loads. Exceeding these limits damages your vehicle. Check your owner’s manual for roof rack ratings. Distribute weight evenly inside the carrier. Heavy items go in the center. Lighter items fill the gaps. Stay within the specified capacity for safety.

4. Evaluate Opening Style

   Consider how you access your gear. Hard shells like the Runave 70 in feature dual-side opening. This allows access from either side of the vehicle. You do not need to climb over. Soft shells usually open from the top. The MeeFar bag requires lifting the lid. Dual-side access is convenient in tight parking spots. Top opening is standard for most carriers. Choose based on your typical loading environment.

5. Confirm Waterproofing Needs

   Ensure your gear stays dry. The MeeFar 21 cu ft Roof Bag offers 100% waterproofing. This is critical for electronics or clothes. Soft shells rely on sealed zippers. Hard shells use gaskets and seals. The Sailnovo Soft Roof Bag is also waterproof. Check for drainage holes. Proper sealing prevents leaks during rain. Inspect seals before each trip. Replace worn gaskets promptly. Waterproofing protects your cargo from weather damage.

Frequently asked questions

See also

• best roof cargo boxes under 150
• best roof cargo boxes under 300