Trailer Tongue Weight Lever Measurement

Method and units

For a stationary trailer with supports at coupler x=0 and axle x=A, scale located at x=s, moment balance about the axle gives tongue load = scale reading × (A−s)/A. If total loaded trailer weight is supplied, tongue fraction = tongue load ÷ total × 100.

Worked example

A 500 kg scale reading 300 mm behind the coupler, with axle 3,000 mm behind it, implies about 450 kg at the coupler. On a 2,000 kg loaded trailer that is 22.5%.

Supported inputs and interpretation

Scale reading 0.1–10,000 kg; scale point from coupler 0–5,000 mm and before axle; axle distance 1–10,000 mm; trailer weight 0.1–50,000 kg. Results are rounded for display only; internal calculations retain full JavaScript precision. Entered measurements and assumptions determine the answer.

References and limitations

The equations here use the stated unit conversions and geometric or accounting relationships; no empirical vehicle limits or manufacturer presets are supplied.

Assumes static level geometry, known support locations and a scale between coupler and axle. This is not a target recommendation or loading approval. Follow the trailer/vehicle manufacturer limits and use a suitable rated scale; verify setup with a qualified professional.

Related calculators

• Cargo Axle Load Distribution
• Trailer Loading Ramp Angle

This planner performs the stated arithmetic; it is not a vehicle inspection, engineering approval, manufacturer's recommendation or professional review.