Cargo carriers that fit on the roof of your vehicle are available in many designs and sizes, so whether you want a small carrier to hold a few items or a larger one that guarantees to carry a lot more, finding it is easier than you think.
Roof Cargo Boxes are measured by the cubic feet they can hold, so it is easy to compare different ones until you find the one you want.
If you want a super-large cargo carrier, you’re in luck because there are numerous ones that can accommodate you, and they cost a lot less than you might think.
So? – What Is the Biggest Roof Box Available? – The biggest and best roof box currently available is the Thule Force XT XL delivering a spacious 22 cu ft of storage.
- Best Option for Cargo Box - Thule Force Cargo Box
- Best Option for Carrier Bag - Sherpak Go! Waterproof Rooftop Cargo Carrier
- Best for Large Volume - FabSelection Water-Resistant Cargo Carrier Bag
Table of Contents
Our Favourite Biggest Roof Box
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| Volume | Size | Highlights | Rating | |
|---|---|---|---|---|
 Highland 1038900 Rainproof Cargo Carrier | 15 cu ft | L: 38" W: 38" H: 18" | 1. Mounts on virtually all roof racks. 2. Rainproof. 3. Concealed zippers. |  |
 Pilot Automotive Aerodynamic Cargo Carrier | 15 cu ft | L: 53" W: 31" H: 17" | 1. Reduce drag and save gas. 2. Folds flat for easy storage. 3. Weather resistant. | |
 Keeper 07204 Waterproof Cargo Bag | 15 cu ft | L: 44" W: 34" H: 17" | 1. Folds compact for easy storage. 2. Soft sides flex to fit odd-shaped loads. 3. Premium Waterproof. |  |
 Sherpak Go! Waterproof Rooftop Cargo Carrier | 15 cu ft | L: 45" W: 37" H: 15.5" | 1. Heavy Duty UV-Resistant Vinyl. 2. A #10 coil zipper. 3. Universal Fit Without the Use of Roof Racks. | |
 Thule 869 Interstate Roof Pouch Bag | 16 cu ft | L: 48" W: 38" H: 18" | 1. PVC-free construction. 2. Double-stitched webbing straps. 3. Fits Thule AeroBlade and SquareBar. | |
 SportRack SR7017 Horizon Car Box | 17 cu ft | L: 91.0" W: 30.7" H: 16.5" | 1. ABS material to reduce impact. 2. Holds 4-6 pairs of skis or 3-4 snowboards. 3. Passenger side opening. | |
 STDY Rooftop Cargo Top Carrier Bag | 20 cu ft | L: 51" W: 40" H: 17" | 1. Waterproof material lightweight. 2. Rubber covered handle for easy loading. 3. Specially design buckles for safety. | |
 FabSelection Water-Resistant Cargo Carrier Bag | 30 cu ft | L: 63" W: 43" H: 18" | 1. Coated with abrasion-resistant waterproof vinyl. 2. Foldable design. 3. Two way nylon zipper and three sides open setting ways. | |
 Thule Force Cargo Box | 21 cu ft | L: 92.5" W: 36" H: 18" | 1. Diamond-Textured AeroSkin Lid. 2. Hold 5-7 skis and 3-5 snowboards. 3. Dual-Side Opening. |  |
Well-Made Cargo Carriers That Make a Difference
If you’re going skiing, hunting, or camping, or if you simply have a long-term trip planned, having a rooftop cargo carrier can save you a lot of room in your vehicle, which is especially useful if you have very little trunk space.
Finding the biggest roof box is easier if you shop online because you can even get full-color photographs of each carrier that helps you get the one that will best suit your needs. You can visualize what it will look like on your vehicle and get the details you need to make sure you get one that can carry your belongings on your next outing.
Highland 1038900 Rainproof Cargo Carrier
The Highland rainproof rooftop cargo carrier holds up to 15 cubic feet of equipment and other items and even comes with a rain flap that makes it easier to get to the items inside when you need to.
You can mount it on nearly all vehicles that have a factory or after-market roof rack attached, and at less than $50, it is a carrier you can count on without breaking the bank. It has welded seams for extra longevity and a convenient storage bag that you can put it in when it’s not in use.
Pilot Automotive Aerodynamic Cargo Carrier
The Navigator CG-08 cargo carrier is aerodynamically designed and made to reduce drag so that you can save money on your fuel bill. You can attach it to either side rails or cross bars and even fold it flat if you aren’t using it.
It is so versatile that it will fit most SUVs and vans, and its 15-cubic-foot size makes it perfect for people who wish to store a lot of items when going camping or hiking. At a size of 53” x 31” x 17”, you can store everything from snowboards to fishing gear and hiking boots to skis.
Keeper 07204 Waterproof Cargo Bag
When you’re looking for the biggest roof box, you also want one that is high-quality and preferably waterproof, and the Keeper waterproof cargo bag is perfect every time.
It is great for standard vehicles and smaller SUVs, and its 15-cubic-foot size means it will hold much more than you think. It even has soft sides that allow you to store odd-shaped items conveniently, and it folds into a compact size when it’s not in use.
Sherpak Go! Waterproof Rooftop Cargo Carrier
Made with heavy-duty materials such as vinyl that is both cold- and UV-resistant, the Sherpak Go! waterproof cargo carrier even has welded seams that help it withstand the elements regardless of how harsh the weather is.
Its large 15-cubic-foot size means it can accommodate the bulkiest of items, and it is so versatile that it will fit perfectly on cars and SUVs without a roof rack. It will strap on easily and quickly to most vehicles, and its 15.5” x 37” x 45” size is perfect for skis, snowboards, and a whole lot more.
Thule 869 Interstate Roof Pouch Bag
The Thule 869 Interstate Bag holds 16 cubic feet worth of items and is a heavy-duty bag with webbing straps that are double-stitched so that you can easily attach it to roof rack crossbars or raised rails.
If you’re interested in finding the biggest roof box for your car or SUV, this is definitely one to consider because it is both sturdy and versatile. The padded base means it will never damage the roof of your vehicle, and it is also water-resistant and can handle the elements with ease.
SportRack SR7017 Horizon Car Box
With an extra-large, 17-cubic-foot design, the SportRack Horizon cartop box is a bit pricey, but is meant to last for a lifetime. Made out of impact-resistant ABS plastic, the carrier has a passenger side opening so that you can open and close it safely.
The quick-release kit makes installation fast and simple, and it is so large that it can hold up to six pairs of skis or four snowboards. It is 91” x 30.7” x 16.5” in size and is made to fit most round or square racks, including most factory-made racks.
STDY Rooftop Cargo Top Carrier Bag
With a waterproof design and high-quality polyester materials, the STDY Rooftop Bag can hold up to 20 cubic feet of items, making it one of the largest cargo carriers on the market.
You can store sleeping bags, luggage, fishing or camping equipment, and lots of other items to make your next outing a success with this bag. When you’re not using it, you can fold it and store it neatly somewhere, and it is super easy to install even for people who aren’t mechanically inclined.
FabSelection Water-Resistant Cargo Carrier Bag
If you need the biggest roof box for your next camping or skiing trip, you can’t beat the FabSelection water-resistant cargo carrier. With the ability to hold a whopping 30 cubic feet of items, this carrier bag is the perfect addition to any large family’s next outing.
It has a very big size – 63” x 43” x 18” – and weighs just under 9 lbs., making it simple and fast to install and remove. It is also able to accommodate most sedans, SUVs, and minivans, even those with no roof rack installed.
Thule Force Cargo Box
With 21 cubic feet of space, the Thule Force cargo box is a hard-shell carrier that provides the ultimate protection from the elements.
It is also aerodynamically designed for great wind resistance and the ability to save money on your utility bill, and the enclosed mounting system allows you to install the box in five minutes or less. A bit pricey, but well worth the price, considering how well-protected the items are and how long it will last.
How Much Weight Can a Roof Box Hold?
Most roof box manufacturers provide a rating that helps you determine how much weight your cargo carrier will hold. However, it is important to note that a cargo carrier that is rated at 165 lbs., for example, doesn’t necessarily hold 165 lbs. worth of items.
If you have racks or crossbars on your vehicle, you have to take into consideration the weight of those as well. In other words, if those racks weigh 30 lbs. and your carrier has a rating of 150 lbs., you can only load up to 120 lbs. worth of items. Otherwise, it can damage your vehicle’s roof.
You also have to take into consideration the weight rating of the roof itself. If the cargo carrier you choose has a rating of 200 lbs. and your roof rack has a rating of 250 lbs., but your vehicle’s roof only has a rating of 100 lbs., you can still only load up to 100 lbs. of items in your cargo carrier.
Remember, the goal is to not cause any damage to the top of your vehicle, so it is crucial that you pay attention to the ratings and never try to push the limits of the racks and cargo carrier you’ve chosen. As a general rule, the ratings on most large cargo carriers range from 100 to 165 lbs., but again, you’ll have to check with your carrier’s manufacturer to determine the exact number that applies to you.
Once you know the limits for both your vehicle and your cargo carrier, you can get a better idea of how much stuff you can load into the carrier.
How Much Can You Fit Into a Cargo Box?
Most cargo carriers refer to cubic feet when describing how much the carrier can accommodate, but to make things a little simpler, there are some basic guidelines that you can follow. A standard airline carryon bag is 22” high and 14” deep, and here are some numbers you can keep in mind when choosing your cargo carrier:
- 18 cubic feet of space: accommodates 12.5 carryon bags
- 15 cubic feet of space: accommodates 10.5 carryon bags
- 12 cubic feet of space: accommodates 8.5 carryon bags
- 10 cubic feet of space: accommodates 7 carryon bags
- 9 cubic feet of space: accommodates 6.3 carryon bags
As you can see from this example, most cargo carriers can accommodate quite a bit of items, making that next camping or fishing trip a lot easier on you. The biggest roof box is likely to provide roughly 20 to 21 cubic feet of space, meaning even large families should be accommodated when they need to store a lot of items for their next trip.
