Know Your Trailer Weights
An interactive guide to ATM, GTM, GCM and towball weight.
Aggregate Trailer Mass
The maximum allowed total trailer weight when fully loaded and unhitched from the tow vehicle.
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Gross Trailer Mass
The total weight carried by the trailer wheels when fully loaded and attached to the tow vehicle.
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Gross Combined Mass
The combined fully loaded weight of your tow vehicle and trailer when hitched together.
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Towball Weight
The downward weight of the trailer coupling on the tow vehicle’s towball.
Towball Weight = ATM − GTM
Trailer Weight Calculator
Enter your known weights in kilograms. The calculator estimates towball weight and checks common limits.