What are car roof weight limits?
Monday 14th July 2025
Do you need more space for your next adventure? If you’re planning a road trip, you might have considered a roof box or roof rack to give you some breathing room inside the car – or to cram in as much as possible! It can be useful to utilise the area above your head, but you must check your vehicle is suitable to handle it first.?
Find out how the weight limit impacts your vehicle, how to use a roof rack, and how to have a safer journey with extra storage on top of your car.?
What am I allowed to carry on my car roof?
Legally, in the UK, you’re allowed to carry roof racks, roof boxes, and roof tents on your car roof. These items can include storing camping gear, extra luggage, sports equipment, and bicycles. However, it’s vital you don’t overload your car and keep in mind your safety and the safety of other road users. Everything should be properly secured, and visibility or aerodynamics should not be impaired.
You should also consider the total height of your vehicle once you’ve added extra storage to the roof of your car. Make sure you know how tall your vehicle is with it attached, otherwise it could prevent you from entering car parks or low-clearance areas – and you don’t want the embarrassment of getting stuck under a height barrier and your possessions getting damaged or scattered all over the road!
How much weight can I put on the roof of my car?
The weight limits will differ from car to car; there is no set amount to go by. You can find this information in two places:
- your car’s user manual/manufacturer guidelines
- on the sticker located on the driver’s door pillar
All weight limits should include the bars, attachments and materials used to make the roof racks and roof boxes – it’s really important you keep this in mind when calculating the roof load.
Types of roof load
Static roof load
- Refers to how much weight your vehicle can safely hold when your vehicle is stationary.
- Determined by the make, design, and material of your car.
- Usually 3-5x greater than the maximum load allowed for a moving vehicle.
- Important consideration when fitting a roof tent (as you have added weight of the people inside, but your vehicle is stationary).
Dynamic roof load
- Refers to the extra weight and resistance of your car while in motion.
- The faster your vehicle travels, the greater the dynamic roof load.
- You should be mindful of your speed, the weather, and other drivers when you’re travelling with dynamic roof load.
- Factors such as turning corners, breaking, hitting bumps, and driving on an incline can impact this.
How to calculate roof loads
Some car manufacturers list a dynamic roof load limit – the maximum weight the roof can safely carry while driving. You can estimate the static roof load limit (when the car is stationary) based on this figure.
- Minimum static load = Dynamic roof load × 3
- Maximum static load = Dynamic roof load × 5
For example, if your car’s dynamic roof load limit is 50?kg, the static load would be between 150kg and 250kg. Always check your car and roof rack manuals, as these figures can vary!
Roof rack weight limit: Tent + gear must be less than the dynamic roof rack limit.
Vehicle roof load limit: Tent + gear + rack weight must be less than the car’s dynamic roof load limit.
How should weight be carried on a roof rack?
According to Rule 98 of The Highway Code, you must secure your load and it must not stick out dangerously. We also recommend you:
- weigh everything your vehicle will be carrying beforehand
- ensure the front of the load is safely secure, as airflow will try to lift it
- ensure the rear is safely secure to prevent a heavy load from sliding when braking
- stop regularly to ensure straps and ropes haven’t come loose
- aim to carry heavier items inside the car and lighter loads on the roof
- consider the extra height of your vehicle when entering car parks and low-clearance areas
- ensure any items on the roof don’t obstruct your vision
How can Formula One Autocentres help with roof weight limits?
Before you set off on your trip, you should ensure your vehicle is properly maintained and prepared. To do this, book a range of our free checks today – from brakes, wheels, and suspension – or take advantage of our free 10-point safety check! Find your local Formula One Autocentres garage, and be one step closer to your journey of the year.
