Trailer Tongue Weight Calculator
Download on the towball for a loaded trailer, against the limit of your towbar.
Results
Nose weight on the ball
99.0
kg
Mass
1100.0
kg
Margin
-24.0
kg
Percentage
6.82
%
What this tool does
Aim for somewhere between five and fifteen percent of the fully loaded trailer weight; around ten is the usual target for a stable tow. Compare the result with the plate on your towbar and the figure in the vehicle handbook — whichever is lower is your real limit.
Formula
tongue weight = total weight × percentage
Variables
| Symbol | Meaning | Unit |
|---|---|---|
tw | Loaded trailer weight | kg |
cg | Cargo weight | kg |
pc | Tongue weight share | % |
mx | Towbar limit | kg |
TW | Nose weight on the ball | kg |
GT | Mass | kg |
MG | Margin | kg |
PM | Percentage | % |
Worked example
- Loaded trailer weight750 kg
- Cargo weight350 kg
- Tongue weight share9 %
- Towbar limit75 kg
- Nose weight on the ball99.0 kg
- Mass1100.0 kg
- Margin-24.0 kg
- Percentage6.82 %
Limitations
- For work that must comply with a standard or be signed off, check the result against the applicable code and have it reviewed by a qualified engineer.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
Frequently asked questions
Why does tongue weight matter so much?
Because it is what stops a trailer swaying. Too little nose weight and the trailer begins to fishtail at speed, a situation that gets worse the harder you try to correct it; too much and it lifts the tow vehicle's front wheels and spoils the steering and braking. Loading heavy items slightly ahead of the trailer axle is the usual fix.