Trailer Tongue Weight Calculator

About this calculator

Tongue weight is the downward force the trailer's coupler exerts on the tow vehicle's hitch, and it should sit within about 10–15% of the loaded trailer's total weight: tongue weight % = tongue weight ÷ total loaded trailer weight × 100. Too little tongue weight (below roughly 10%) allows the trailer to sway dangerously at highway speed, while too much (above roughly 15%) overloads the tow vehicle's rear axle and hitch, causing poor steering and braking control.

Trailer owners and RV towers check this before every trip because load placement inside the trailer — not just total weight — determines tongue weight, and cargo shifted too far back is one of the most common causes of dangerous trailer sway, a problem that is often blamed on wind or vehicle mismatch when the real cause is simply an out-of-range tongue weight percentage.

This calculator takes your tongue weight and loaded trailer weight and returns the percentage along with whether it falls in the recommended 10–15% range, so you can check your load is safe before you get on the highway.