Size Matters: How to Choose the Right Size Cargo Box

Key Points

  • Knowing how to choose the right size cargo box is an important step to traveling comfortably and safely while hauling a lot of gear.

  • Cargo boxes are aerodynamic and come in a variety of different sizes and materials.

  • When learning how to choose the right size cargo box, do your research and select a box that best suits your needs and the size of your car.

  • Thule, Yakima, and INNO are quality cargo box brands that offer long-lasting products.

Outdoors enthusiasts know that gear is a necessary aspect of any adventure. From camping equipment to sporting gear to everyday essentials, it's tiring, cumbersome, and frustrating to constantly pack and unpack all your gear to find the exact item needed for that day’s activities. That's why knowing how to choose the right size cargo box for your vehicle is vital.

A cargo box is a convenient solution if you're looking for a secure and convenient way to transport your belongings. They come in various sizes to accommodate any load and are perfect for road trips, camping trips, and even everyday use. With this guide, learn how to choose the right size cargo box and enjoy a hassle-free adventure.

Cargo boxes provide a convenient and secure way to transport your gear on road trips. Learn how to choose the right size cargo box with this guide.

Do You Need a Cargo Box?

If you're someone who adventures regularly, has a big crew, or packs heavy, then, yes, you need a cargo box. When it comes to hauling your gear, a cargo box makes a world of difference.

Think back to any road trip with friends or family. Remember how bodies and bags and helmets and coolers were all shoved into any and every nook and cranny and the drive felt endlessly long and cramped?

No one wants to go through that again. That's where a cargo box comes in handy. One of the main benefits of a cargo box is its ability to free up space inside your vehicle.

As gear experts and writers for GearLab, Lauren DeLaunay and David Wise, say, “A cargo box can help you stay organized and maximize space inside your vehicle. The more dialed-in your car set-up is, the more you can focus on enjoying the open road and the adventures awaiting you at a new destination.”

No more cramped road trips. No more, "There wasn't any room." A cargo box makes it easy to bring along more gear and equipment without cluttering up the inside of your car. This is especially helpful for folks with families who pack a lot of items for long trips or friends who over-pack and haul extra gear with them.

Even more than that though, it makes it possible for those who just need more things — babies, elderly adults, those with a disability — to be able to travel and bring everything they need for a safe and fun trip. Is your mom saying she's only coming if you bring the air mattress? No problem!

Not only does a cargo box provide storage while on the move, but it also keeps your belongings safe and protected from the elements. Cargo boxes are known for keeping your gear extremely safe. Your belongings are stored out of sight and are less likely to be stolen. Better yet, most cargo boxes are big enough to hold those bigger-ticket items like snowboards, skis, and tents.

Cargo boxes also offer convenience when it comes to loading and unloading.

Overall, cargo boxes are durable and long-lasting investments.

How Do You Choose a Cargo Box?

When it comes to selecting the right cargo box for your specific needs, three crucial aspects to take into account are size, material, and how easy it is to load and unload.


Consider the type of gear you want to transport. If you plan on taking a lot of bulky items like camping equipment or skis, choose a larger cargo box. If you're transporting smaller items such as clothing and personal items, a smaller cargo box is sufficient.

How many people are you traveling with? If you have a larger group, a larger cargo box is necessary to accommodate everyone's gear.


If you frequently take road trips or camp in areas with high temperatures, avoid cargo boxes made of plastic. When they get too hot, these materials trap heat, which results in potential damage to your stored items. It also doesn't help to have the sun beating down on it for a long road trip on hot asphalt roads.

An alternative is a cargo box made of composite or aluminum. These materials, according to critics and customers, offer superior resistance to harsh weather conditions, thereby keeping belongings safe.

Ease of Loading

The goal with your new cargo box isn't to make your life harder, but easier. Make sure whatever you buy simplifies your life rather than complicates it.

Many cargo boxes come equipped with additional features such as dual-sided openings for easy loading and unloading. Some even have built-in ramps for loading larger items like skis or bicycles. While these features come at a higher cost, they greatly enhance the overall convenience and ease of use.

Choosing the Right Size Cargo Box for Your Vehicle

When it comes to selecting the perfect cargo box, compatibility with your vehicle is key. The last thing you want is to invest in a cargo box that is either too large or too small for your vehicle. Be like Goldilocks when it comes to your cargo box — choose the one that's just right.

It's easiest to fit a cargo box in the bed of a truck or on the roof of your car. If you don't have a roof rack, you're not quite ready for this guide. It's not impossible to fit a small cargo box in the back of your car, but it's not the ideal way to transport it.

To determine if a cargo box fits your vehicle, measure the length, width, and height of the available space on your roof rack or bed rail. Don't forget to take into account any other items you plan on transporting, like a rooftop tent, bike rack, skis, or a snowboard.

Weight is another important factor. Some cars are not designed to handle the added weight of a cargo box, so it's essential to check your vehicle's weight capacity before making a purchase. Your car needs to not only be able to hold the weight of the cargo box but the weight of whatever gear goes inside.

The shape of your car is also worth taking into account. Some cargo boxes are specifically designed for certain types of vehicles, such as SUVs or hatchbacks. Most boxes have a list of cars and models with which they're compatible in the product specifications.

By following these guidelines, you ensure you choose a cargo box that not only fits your car but also enhances the overall convenience and enjoyment of your trips.

For detailed information about your car and selecting the right size cargo box for it, this REI sizing guide is a helpful tool. 

Installing a Cargo Box

Once you determine the size and weight of the cargo box that's compatible with your car, it's time to install and secure it.

Many cargo boxes come with specific mounting hardware to ensure that they tightly attach to your vehicle. Follow the manufacturer's instructions on installation and always use the proper tools and equipment.

Double-check that the cargo box is properly secured and locked before hitting the road. Don't be that person who finds their underwear, mittens, and pillows floating away in their rearview mirror. Be the person who's carefree and singing Tom Petty at the top of their lungs eager to start their adventure.

What Happens If You Use a Cargo Box That Is Too Big?

When it comes to choosing the right size cargo box, bigger isn't always better.

In fact, having a cargo box that's too big creates all kinds of unfortunate issues. Not only does it take up valuable space on your roof, but it's difficult to maneuver, challenging to load and unload, and above all else, dangerous.

A box that's too big doesn't securely mount to your roof. If it's unstable, it's possible your gear falls out or the box falls off completely while driving. This leads to damage to your vehicle or causes accidents. That's why taking accurate measurements of your roof before buying a cargo box is a must.

Using a cargo box that's too big means you're less aerodynamic, sending your mileage and gas output way up. A larger box creates more wind resistance and drag, which causes your car to work harder and burn more fuel. This ultimately ends up costing you more money in the long run.

If you have a larger cargo box, it increases the height of your vehicle. This poses a problem when going through certain drive-thrus or parking garages with low clearance. Don't knock all your perfectly packed items clean off your car because you forgot to account for this.

What About Cargo Box Overhang?

Overhang is when your cargo box is a little larger than your roof, so it hangs over the windshield.

A slight overhang is fine, but it's a delicate balance. If you have too much overhang, your box is too big. This causes it to become unstable and puts too much strain on the roof rack.

Properly anchor any excess overhang with straps or bungee cords. This ensures that your cargo box doesn't detach and injure someone while driving.

Some states have regulations on the amount of overhang your vehicle is allowed, so check with local law enforcement before installing a cargo box.

Do Cargo Boxes Damage Your Car?

Cargo boxes are specifically designed to be used on your car without causing any damage. There's little chance of you causing serious damage to the surface of the vehicle unless the box does not fit properly.

With hard-sided boxes, there's always a risk of scratching the paint or denting your vehicle. Remove the cargo box from your roof when it's not in use to keep this from happening.

As long as you read the instructions from the manufacturer carefully before installation and de-installation, you ensure your car is free from harm.

Is Aerodynamics Really a Thing With Cargo Boxes?

Above all else, your cargo box is designed to make things more convenient for you. You don't want it to negatively impact the fuel efficiency or stability of your car. This is where aerodynamics come into play.

A cargo box with a streamlined shape minimizes wind resistance and drag while improving fuel efficiency. A balanced and stable design enhances the overall stability of your car while driving.

Some features usually found in aerodynamic cargo boxes designed to reduce wind resistance and drag include:

  • Rounded or sloping front and rear edges

  • A smooth, polished surface

  • An attached aerodynamic fairing device

Cargo boxes that are built without aerodynamics in mind are much louder, create serious drag which requires more fuel usage, and make driving and transporting your gear less safe.

Do Cargo Boxes Keep My Gear Secure?

Yes, cargo boxes are safe and secure. Most models come with built-in locks to deter theft and many have reinforced lids that provide extra protection. Some are made of high-quality materials like ABS plastic or aluminum which is strong, durable, and impact resistant so damage to your items is less likely.

Packing a Cargo Box

Cargo boxes are made to hold your big, bulky gear — think tents, sleeping bags, skis and snowboards, fishing poles, helmets, and other outdoor adventure items.

How you pack is just as important as what you pack. It's crucial to plan ahead and give yourself time to properly pack your items so everything fits comfortably. Packing your cargo box effectively gives you more room for more gear and ensures your gear stays put and doesn't move around during transportation.

If your gear isn't packed strategically and shifts as you drive, the weight distribution in your car becomes uneven and unpredictable. To avoid that, pack your gear tightly. Leave no gap or hole unstuffed.

Place heavier items at the bottom of the box and lighter items on top. This keeps the center of gravity low, preventing the box from becoming top-heavy. Also, use straps or bungee cords to keep items from shifting while on the road.

Don't worry about your gear breaking through your cargo box. They're made with strong materials and designed to hold heavy duty gear.

Utilize smaller bags or containers inside the cargo box. This not only maintains good organization but also makes it easier to pack and unpack. Plus, it gives you quick and easy access to the items you need.

Some items are not safe to pack in a cargo box. Keep items that are sensitive to heat or cold, such as electronic devices, in the car with you or packed in insulated bags. Because most cargo boxes are black, they trap heat, so you run the risk of your devices overheating.

Avoid packing items in your cargo box that are dangerous in the case of an accident, like sharp or heavy objects.

Following these packing tips ensures you make the most of your cargo box.

Maintaining Your Cargo Box for the Long Haul

Cargo boxes are made of durable materials, so they're sturdy enough to withstand wind, rain, storms, and constant loading and unloading. As with anything, however, if you want your cargo box to last for the long haul, take care of it.

Too much direct sunlight or hot temperatures over a long period of time warps the box. Similarly, don't store it in a place that gets too cold. This causes the box to crack.

Store your cargo box in a relatively cool place out of direct sunlight. Be sure to store it on its base. Storing it on its end or sides causes scuffs or worse. If it's leaning against something, you run the risk of your box damaging the wall, falling down and damaging the floor, or falling on someone.

It's recommended you clean your cargo box every so often. Do not bring it through a drive-through car wash while it's still attached to your car. This not only damages the box, but the infrastructure of the car wash as well. It's best practice to hand wash both the inside and the outside of your box instead.

Quality Cargo Boxes on the Market

If you're in the market for a cargo box, you've probably come across the Thule and Yakima brands. INNO is a lesser-known brand it's absolutely worth exploring. It doesn't have the clout or long-standing brand recognition that Thule and Yakima have, but the specs and reviews for INNO boxes are spectacular.

All three brands are easily found and compared at REI.

Each brand has a variety of options when it comes to price, size, material, and features.


One major difference between the three is the price point. Thule cargo boxes are more expensive thanks to their higher-quality materials and offer more advanced features, while Yakima and INNO have more budget-friendly options. All three brands have different models with varying degrees of features and functionalities. The fewer the features, the lower the price. If you want the built-out, feature-heavy cargo box, the price is higher.


Another difference is the range of sizes available. Thule offers a wider variety of sizes, with options for both smaller and larger vehicles. Yakima focuses on medium-sized cargo boxes. INNO offers a little bit of both.


When it comes to the material, Thule and INNO cargo boxes are made with a hard plastic shell. Yakima offers a mix of plastic and metal options. The hard plastic shell of Thule boxes provides added durability and weather resistance, while the plastic and metal combination of Yakima boxes provides a balance of strength and weight. INNO boxes are made of plastic and have an injection-molded bottom that makes the thickness of the material uniform and particularly strong.


Thule cargo boxes have a sleek, aerodynamic design that reduces wind resistance and noise while driving. INNO boxes are similarly designed. Yakima boxes have a more traditional design that prioritizes function over form.

If color preference matters to you, unfortunately, your choices are fairly limited. It's either black or white. For most models, white isn't even an option. Keep in mind what Ricardo Tisci said: "Black is always elegant. It is the most complete color in the whole world, made of all the colors in the palette." With a black cargo box, you're driving with the whole world of colors on top of your roof.

Ultimately, the choice between Thule, Yakima, and INNO comes down to your individual needs and preferences. If you are looking for a high-quality cargo box with a wider range of sizes and advanced features, Thule is the better choice. If you're on a budget and want general usability over added features, INNO or Yakima is the way to go.

Before you throw down the big bucks for one of the cargo boxes discussed above, explore options for used cargo boxes. Shopping for adventure and outdoor gear gets expensive quickly, so don't spend money where you don't need to. Buy quality gear at just a fraction of the price at sites like these that offer great deals.

Don't Let Anyone Tell You Differently: Size Matters

If you're an adventurer, thrill seeker, mountain lover, day hiker, or party host, you know the importance of safely and conveniently storing and transporting all your gear.

The wrong-size cargo box is not only a hassle to install and use, but it also leaves you without enough room in your vehicle or makes your trip dangerous.

Choosing the right size cargo box ensures that you have enough space for all of your gear and that the box fits properly on your vehicle. With a secure and aerodynamic cargo box, enjoy smooth sailing on your next outdoor adventure.

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