Car roof box buying guide: How to find the best roof box for your car

What you need to know to maximise your car space and hit the road without leaving anything behind.

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Key facts about car roof box:

  • Car roof boxes (also known as cargo boxes) are storage spaces that are fitted to your car's roof and mounted to your car's built-in or installed roof racks.
  • With a roof box, you can stop stressing about how you can possibly pack everything you need for a camping weekend away with the kids or a road trip with friends and family.
  • The extra storage space can make it easy to transport bicycles, ski gear, fishing equipment and other large items.

Size and shape

When choosing a roof box, the most important factor to consider is the size and shape of the roof box.

While roof boxes can reasonably fit on most cars, varying sizes will provide different amounts of storage. Roof boxes are usually rectangular, but their dimensions vary. It's more helpful to compare the dimensions of the roof box, rather than its stated capacity. Extra litres in capacity could translate to only a few extra centimetres in height or length, which realistically won't make much difference. Remember to check the dimensions of the roof box against the dimensions of your car; you will want to be able to open your car's tailgate completely without the tailgate spoiler hitting the rear of your box.

Roof boxes come in half, medium and full-widths in both long and short options. With a half-width box, you can carry additional gear on your roof, such as a bike or canoe. Medium-width boxes typically suit a family of four. A long, full-width roof box that covers your whole roof offers more storage space but requires two people to maneuver it. A long roof box would suit those carrying skis.

Standard roof box sizes:

Narrow-width60cm wide or less
  • Gives you extra space on the roof for other gear such as bikes.
  • Long narrow-width boxes are suitable for carrying skis.
Medium-width60cm to 75cm wide
  • Most popular width for families as they are easier to lift and move than full-width boxes, but still provide adequate storage space.
Full-width75cm to 95cm wide
  • Allows you to maximise roof storage space.
  • Requires two people to lift and move.
ShortLess than 1.5 metres long
  • Suitable for smaller cars (eg hatchbacks).
  • Can be stored more easily than long boxes when not in use.
LongOver 2 metres long
  • For those who want the biggest box.
  • Should provide adequate storage for a family of 4 to 5.
  • Can be difficult to lift and store.
Do I need a roof rack?

Yes, if you want to attach a roof box to your car, you need a roof rack. You will need to install the roof bars before you can fit a roof box to your car. Though your roof box doesn't have to be a particular shape for your car, your roof bars do. Check what roof racks fit your car by finding out your vehicle's roof type. For more information, about what roof bars and roof rack system to purchase, check out our roof rack buying guide

Height restrictions

When adding a roof box, it's important to check the increased height of your car and be aware of height restrictions of tunnels, parking lots and other restricted height spaces. Height restrictions in Australia depend on the location and the road.

If you buy a roof box without checking the total height of your car, you could end up trying to drive into a restricted height space, damage your car and roof box, and potentially face heavy fines.

Before buying a roof box, check the following heights:

  • Car
  • Roof box
  • Roof rack

Add the three heights together to get the total height of your vehicle with the roof box and add an extra margin of at least a few centimetres just to be safe. To find out the height of your car, check your car manual. If you are storing anything additional on your car, such as an upright bicycle, make sure to measure from the highest point.

Once you are on the road, keep an eye out for low clearance roads, tunnels, underpasses and parking lot entrances.

How to compare car roof boxes

A car roof box can cost you from around $499 up to $1999 depending on the size of the box, the material used and the brand.

To work out which roof box is right for you, consider these essential features:


Does your roof box need to withstand extreme changes in temperature, wet conditions or high impact? If so, consider a higher-end material. The cheaper the box, the more likely the material will be thinner, less secure and less robust. Cheaper boxes are generally made of a thinner plastic that could rattle a lot after prolonged use and crack in cold temperatures. Opt for UV-protected ABS plastic or fibreglass reinforced plastic that will better withstand wear and tear, as well as rain, extreme temperatures and high impact.

Locking system security

Consider if you would prefer a secure locking system or are happy with a simple, single lock design. More high-end options generally offer better security. A single lock in the middle may be easier to pry open from the sides and allow you to just put your arm in and pull things out. A box with multiple locks or a central locking system is ideal for safety. However, boxes with a central locking system can be difficult to close, as the central lock needs to be turned while both the front and back of the box are shut properly. This can require three hands if a box is full.


If you want your box to be fully waterproof, you will need to look out for a flush fitting lid and base design.

Dual side openings

Roof boxes that can open from both the left and right sides tend to be more practical. It's particularly handy on full-width boxes on taller cars, as narrower boxes will still need to be on one side of the car and can't be reached from the other side. Rear opening boxes provide access from three sides at once.


There are various roof box accessories you might want to consider.

  • Cover. Purchasing a roof box lid cover is not essential, but good if you want to protect your box from scratches and dirt when it's being stored.
  • Light. This will be helpful when you're trying to unload your box in low light conditions or at night.
  • Ski carrier. Some boxes offer specific ski carriers to hold your skis securely inside the box. Other boxes feature a "safety nose", an extra internal energy-absorbing barrier to prevent skis from breaking through the front of the box during a collision.
  • Wall holder. You might want to use a wall holder in your garage to store your roof box when it is not in use to prevent damage from scratches.
How should I store my roof box?

If you're not leaving your roof box permanently on your car roof, we recommended that you store it horizontally instead of upright which can cause damage to the end or side of the box. If space is an issue, you can purchase a hoist system so that your box can be suspended from your garage roof, or use a wall holder to keep it securely mounted against the wall. Roof boxes should be stored in a cool dry place out of direct sunlight to avoid damage from extreme temperatures and UV rays.

Alternate storage options

If you don't want to shell out the money for a roof box, soft-sided roof bags and roof baskets can give you additional storage for a lower cost.

If you only want to transport your bicycles, you could also opt to get a tow bar or trunk-mounted bike rack instead of investing in a roof box.

Soft-sided roof bagsSoft fabric bags that can be strapped to roof racks or directly to your car's roof.
  • Usually cheaper than roof boxes.
  • Can be folded up for easy storage.
  • Not as secure as hard shell roof boxes.
  • Won't keep your items fully dry.
Roof basketsOpen-air container that requires contents to be strapped into place or covered by a net.
  • Cheaper than roof boxes.
  • Can be used for oversized and irregularly shaped items that can't fit into a roof box.
  • Can't be locked.
  • Not weather-proof.
  • May not keep out bugs.

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