Trailer Tongue Weight Calculator
Ideal trailer tongue load and safe 10 to 15 % band from weight.
What it does
Tongue weight steers the whole rig. Too little and the trailer sways at speed, too much and the tow vehicle squats with light steering, so a measured middle wins.
The tool above turns loaded trailer weight into hitch load. A 5000 lb trailer at 12 % wants 600 lb on the ball, inside a 500 to 750 lb safe band. Metric towers get 2270 kg toward 272 kg, inside 227 to 341 kg.
The 10 to 15 % band is the standard target. It balances sway control against hitch and rear axle limits across bumper pull designs. Fifth wheels run higher pin shares and need their own guide.
Loaded weight is the only input that counts. Dry brochure weights skip water, fuel, food, and toys, which can add many hundred pounds behind the axle.
Adjustment is cargo Tetris. Slide heavy gear forward to add tongue and back to cut it, then reweigh the hitch and check ride height before highway speed.
How to use
- Pick imperial (lb) or metric (kg).
- Enter loaded trailer weight.
- Enter share: 12 suits many rigs.
- Read tongue weight first.
- Read 10 % low and 15 % high.
- Shift cargo and reweigh to land inside.
Formula
- trailer
- Loaded trailer weight with gear aboard.
- share
- Tongue share, in percent.
Share input spans 8 to 15 %, but the safe band shown stays 10 to 15 %. Weigh the hitch with a rated scale, not by lift feel.
Worked example
Example: 5000 lb at 12 %
Imperial defaults: 5000 lb trailer at 12 %. These are also the default values, so the page opens on this answer.
- Trailer: 5000 lb loaded.
- Share: 12 %.
- Tongue: 5000 x 0.12 = 600 lb.
- Low: 5000 x 0.10 = 500 lb minimum.
- High: 5000 x 0.15 = 750 lb maximum.
- Tool shows 600 lb, 500 lb (10 % minimum), 750 lb (15 % maximum).
Reference table
| Trailer | 12 % | Safe band |
|---|---|---|
| 3000 lb | 360 lb | 300 to 450 lb |
| 5000 lb | 600 lb | 500 to 750 lb |
| 7000 lb | 840 lb | 700 to 1050 lb |
| 2270 kg | 272 kg | 227 to 341 kg |
Limits
- Guide only. Hitch, ball, and axle ratings still gate.
- Ignores sway from wind and poor loading height.
- Scale accuracy matters. Bathroom scales need lever rigs.
- Fifth wheel pin shares differ.
Common mistakes
- Using dry weight and running light.
- Loading heavy gear behind the axle.
- Guessing tongue by lift feel.
- Exceeding hitch or rear axle ratings.
- Towing fast to test a sway fix.
Try it yourself
Quick checks. Answers sit tucked under each question.
3000 lb at 12 %?
Tongue is 3000 x 0.12 = 360 lb. Band is 300 to 450 lb.
1500 kg at 12 %?
Tongue is 1500 x 0.12 = 180 kg. Band is 150 to 225 kg.
Questions
What tongue weight?
Multiply loaded trailer weight by the share. A 5000 lb trailer at 12 % needs 600 lb on the hitch.
What is the safe band?
Keep 10 to 15 % of loaded trailer on the hitch. Here 500 to 750 lb for a 5000 lb trailer.
Light or heavy: which is worse?
Light tongues sway, heavy tongues sag the tow vehicle and lighten steering. Both wear tires and nerves.
Loaded or dry weight?
Weigh loaded for travel: fuel, water, gear, and toys aboard. Dry weights mislead by hundreds of pounds.
How do I adjust?
Move cargo forward to add tongue, back to cut it, then reweigh. Small moves shift hundreds of pounds.
Does this clear my tow rating?
No. Ratings, brake setup, and hitch class still gate the tow.