Trailer Tongue Weight Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the loaded trailer weight and the measured tow-ball weight.
- Read the percentage and the guidance.
How it works
Tow-ball weight ÷ trailer weight × 100. A common target is around 10% (typically 9–11%).
Worked example
150 kg ball, 1500 kg trailer. = 10% — in the ideal range.
Common mistakes
- Too little ball weight causes dangerous trailer sway.
- Exceeding the vehicle's or tow-bar's rated tow-ball download.
Frequently asked questions
What tow-ball percentage is safe?
Around 10% is the usual aim, within roughly 9–11% — but always stay within your vehicle and tow-bar ratings.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.