How Roof Rack Load Limit Is Calculated
When loading a roof rack or roof box, staying within your roof's rated load capacity matters most. Enter your vehicle's roof load rating, the rack's own weight, and your cargo weight, and this calculator shows the remaining capacity and whether you're over the limit.
The rated load includes the weight of the rack itself, so a heavier rack leaves less room for actual cargo. Using factory roof rails is cheaper to install but often has a lower load limit, while a new crossbar install costs more but some vehicles can then carry heavier loads safely. Driving over the rated limit increases the risk of roof panel deformation or an accident, so always stay within your available capacity.
Frequently Asked Questions
Most vehicles list the dynamic roof load limit (in kg or lb) on a sticker on the driver's door jamb or in the owner's manual.
No — exceeding the rated load raises the risk of roof panel deformation or crossbar failure at highway speed, so always stay within the rating.