🚚 Trailer Tongue Weight Calculator

Tongue weight is the downward force a trailer exerts on the hitch ball — the portion of the trailer's gross weight (GTW) that's transferred onto the tow vehicle.

For a typical bumper-pull trailer, 10-15% of GTW is the recommended tongue weight range, and the physics behind it is straightforward. Below 10%, too much weight sits behind the trailer axle, making the trailer prone to sway (fishtailing) at highway speed — in the worst case leading to a jackknife. Above 15%, the tow vehicle's front axle gets unloaded (lighter steering feel) while the rear axle and hitch carry excess load, increasing tire wear and suspension strain.

For a trailer with a GTW of 2,000 kg, the recommended tongue weight range is 200 kg to 300 kg (2,000 × 10% = 200, 2,000 × 15% = 300).

If you measure a current tongue weight of 250 kg with a tongue scale, that's 250 ÷ 2,000 = 12.5% — inside the recommended range, so the verdict is OK.

This calculator only computes a percentage of GTW, so you should also confirm the hitch/receiver's maximum tongue weight rating and your tow vehicle's payload capacity and GVWR. A percentage that looks fine can still exceed your hitch's rating.

Measure with a dedicated tongue weight scale, or a simple bathroom-scale lever method as an alternative.

Note that gooseneck and 5th-wheel trailers transfer load differently and use a higher recommended ratio of 15-25% instead — this calculator is scoped to bumper-pull trailers, and gooseneck/5th-wheel setups are out of scope.