A rooftop cargo box is one of the most practical upgrades you can make to any SUV or crossover. It doubles your usable storage space without touching the interior or the trunk, keeps everything weatherproof and lockable, and lets you split the load between passengers and gear instead of stacking bags to the ceiling.
The challenge is choosing the right one. Size, opening style, internal capacity, mounting compatibility — there’s a lot to get right. This guide covers the best cargo boxes for SUVs across every use case and price point.
What to Know Before You Buy a Cargo Box
Internal Capacity
Cargo boxes are measured in cubic feet (or liters). A 14–16 cu ft box holds skis, a snowboard, duffel bags, and gear for 2–3 people. An 11–12 cu ft box is better for weekend trips or vehicles with shorter roof spans. Measure your crossbar spread before buying — most boxes require a minimum spread of 24 inches.
Dual-Side Opening vs. Passenger-Side Only
Dual-side opening boxes open from either side — extremely useful in tight parking spots. Single-side boxes (passenger side only) cost less but limit access when you park against a wall or curb. Worth paying for dual-side if you use the box frequently.
Mounting System
Most quality cargo boxes use a U-bolt or clamp system that works on square, round, and aero crossbars. Some systems (like Thule’s EasyFit) can be mounted solo without help. Make sure the box is compatible with your crossbar brand and profile before ordering.
Best Cargo Boxes for SUVs
1. Thule Force XT XL — Best Overall
The Thule Force XT XL is the gold standard for rooftop cargo boxes. At 16 cubic feet, it holds skis up to 215 cm, snowboards, and a full load of duffel bags for a family ski trip. Dual-side opening makes access easy in any parking situation. The PowerClick quick-mount system attaches to your crossbars solo, and the integrated lock secures both the box and the mounting hardware with one key.
Best for: Families, ski trips, and anyone who wants the best all-around cargo box available.
2. Yakima SkyBox 16 — Best Alternative to Thule
The Yakima SkyBox 16 is the main competition to the Force XT XL, and it’s excellent. Same 16 cu ft capacity, dual-side opening, universal mounting hardware, and a sleek low-profile lid design that minimizes wind resistance. The SuperLatch security system locks the lid and the hardware simultaneously. Available in 12 and 21 cu ft versions for different vehicles and needs.
Best for: Yakima ecosystem users, or anyone who wants a premium box that competes directly with Thule.
3. Thule Force XT Sport — Best for Smaller SUVs
At 11 cubic feet, the Force XT Sport is better sized for compact SUVs like the Honda CR-V, Toyota RAV4, and Subaru Forester. It’s lighter, shorter, and easier to handle than the XL version. Same dual-side opening and PowerClick mounting as the larger model. If you don’t need ski capacity and just want general storage for road trips, this is the better choice.
Best for: Compact SUV owners and road-trippers who don’t need ski-length capacity.
4. RoofBag Explorer — Best Budget Cargo Box
If you only need a cargo box a few times a year, the RoofBag Explorer is a smart alternative to a hard-shell box. It’s a soft-sided bag that straps directly to your crossbars, holds 15 cu ft, and packs flat when not in use. It’s waterproof, reinforced at the seams, and costs a fraction of a Thule or Yakima box. Not a replacement for daily or weekly use — but for occasional trips, it gets the job done.
Best for: Occasional users who don’t want to store a full hard-shell box year-round.
Tips for Using a Cargo Box
- Check your garage clearance before installing. Most cargo boxes add 12–16 inches of height to your vehicle.
- Load heavier items low and forward — this keeps the center of gravity stable and reduces buffeting at highway speeds.
- Don’t exceed the box’s load rating — most quality boxes are rated at 165 lbs, but your vehicle’s roof limit is the real constraint.
- Remove the box when not in use if fuel economy matters. An empty cargo box at highway speeds costs you 2–5 mpg in aerodynamic drag.
- Check the lid gasket annually — UV exposure degrades rubber seals over time. A failed gasket means a wet load.
Bottom Line
The Thule Force XT XL is the best cargo box for most SUV owners — it’s large, quiet, and built to last. The Yakima SkyBox 16 matches it on every key metric and is worth considering if you’re already in the Yakima ecosystem. For compact SUVs, the Thule Force XT Sport is better proportioned. And for occasional-use buyers, the RoofBag Explorer offers impressive value.
Measure your crossbar spread and check overhead clearance before ordering — those two steps prevent the most common cargo box mistakes.