If you travel regularly by car, you’re naturally going to want a super-large cargo box for the roof, especially if you plan to be gone for a while. Cargo boxes come in various sizes that are measured by the number of cubic feet they can hold, and they can hold anywhere from nine to 20 cubic feet and sometimes more.
In addition, there are two main types of cargo boxes: the soft-case type that molds to the shape of what’s inside and are easy to install, and the hard-shell case that is usually sleek and aerodynamically designed.
If you want the absolute largest roof box on the market, you should choose one that holds a minimum of 18 cubic feet of items, and below are some of the biggest and best available today.
- Best Largest Cargo Bag - Wisamic Car Rooftop Carrier
- Best Features Cargo Bag - RoofPax Car Rooftop Bag and Cargo Carrier
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Our Favourite Largest Cargo Box








Last update on 2023-09-25 / Affiliate links / Images from Amazon Product Advertising API
RoofPax Car Rooftop Bag and Cargo Carrier
Holding a whopping 18 cubic feet of suitcases and gear, the RoofPax cargo carrier measures roughly 47” x 35” x 20” and can hold up to six suitcases and more. If you have a big family, this is the carrier you want, and it also comes reasonably priced at around $140.
Instead of using straps that go inside the car to tie it down, the RoofPax carrier comes with a total of six door hooks that not only make the carrier more secure, but a lot safer as well.
The carrier is made out of military-grade materials and, therefore, it can withstand even inclement weather conditions and tough wear and tear. It comes complete with a protective mat and ten strong straps that include strap restrainers so that flapping doesn’t occur. It has a heavy-duty zipper that will work properly for a very long time and can be installed either with or without a roof rack.
Of course, RoofPax’s number-one advantage is its super-large size. With this cargo carrier, you will never run out of the room regardless of what you pack inside of it. Your luggage will stay safe and secure inside the carrier, and it even comes with a lifetime warranty on the zippers and buckles, providing you with the peace of mind you definitely deserve.
Oanon Waterproof Car Rooftop Carrier
With a full 20 cubic feet of space, the Oanon car rooftop carrier is a soft-top carrier but is available in a thicker variety as well.
Larger than most other carriers, this one measures 51” x 40” x 17” and is, therefore, perfect for accommodating large families or long-term trips. Made out of top PVC materials, this is one carrier that can easily withstand the elements, and it is always on the list of the largest roof box available.
With its unique design, the Oanon cartop carrier is not water-resistant like other carriers; it is completely waterproof, which makes a big difference. Choosing this carrier means you’ll never have to worry about how much rain you’re getting as you travel because you’ll know your luggage will always be safe and dry. In addition, the enclosed short and long straps mean you can install it within minutes, making it easy to use it immediately.
Easy to install, easy to use, and easy to keep clean, the Oanon cartop carrier is one you won’t regret purchasing, especially since it comes available at a price of under $70. Best of all, it comes with everything you need to use it right out of the packaging, providing you with the convenience you need and deserve when you’re looking for an extra-large cartop carrier.
STDY Waterproof Cartop Carrier
When it comes to the largest roof box on the market, the STDY cartop carrier is one of the best. It provides you with complete waterproof protection year after year and is made out of 1200-Denier polyester material that won’t rip, tear, or crack.
Manufactured in a sleek design and attractive black and teal colors, this carrier holds up to 20 cubic feet of materials so it can accommodate anyone. This is a very durable carrier that is double-stitched for extra longevity, and it is easy to install thanks to the enclosed tie-in straps.
In fact, everything you need to install it properly is included in the package, which means you can take it out and install it as soon as you get it. In addition, if you have oddly shaped items to go inside the carrier, not to worry because the soft shell can accommodate them.
Yet another advantage of the STDY cartop carrier is its portability. The carrier is easily folded into a much smaller shape and even comes with a carrying bag to store it in when it’s not in use. Best of all, it will fit sedans, SUVs, and minivans, making it a very versatile carrier in the end.
Wisamic Car Rooftop Carrier
Last, but not least, this is by far the largest roof box on the list because it can accommodate up to 30 cubic feet of suitcases and other items. Priced at just under $80, the Wisamic carrier is also a reasonably priced product regardless of your budget.
Its overall size is roughly 63” x 43” x 20”, and it even comes with extra-large straps in case you need to attach it to an SUV or other large vehicles.
One advantage of this rooftop carrier is the non-slip grip mat that comes with it, which guarantees you won’t ruin or scratch up any paint on your car’s roof. It has triple-sewn straps that do a great job of keeping the carrier – and the items inside – safe and secure, and it comes with a storage bag that you can store it in when you’re not using it.
The Wisamic cartop carrier is also user-friendly, which means anyone can take it out of the package and start using it immediately. It is also made out of 500D PVC materials and is 100% waterproof and dust-proof, so your carrier will be protected regardless of what you put it through.
This extra-large carrier is exactly what you need for your next trip to the beach or the sports field and provides you with tons of extra storage space that you didn’t have before.