How it works
Each item’s weight is shared between the hitch and the axle depending on where it sits, like a plank resting on two supports. An item right over the ball puts all its weight on the hitch; one right over the axle puts none; one behind the axle actually lifts the tongue.
Tongue share of an item = weight × (L − x) ÷ L
Tongue weight = empty tongue weight + sum of item shares
Tongue % = tongue weight ÷ loaded trailer weight × 100
L is the distance from the ball to the axle center and x the item’s distance from the ball. The calculator also finds where the combined cargo center should sit for 12.5% tongue weight.
Worked example
2,000 lb trailer with 200 lb empty tongue weight, axle 12 ft from the ball, a 1,200 lb pallet 7 ft from the ball and a 600 lb mower at 13 ft.
- Pallet: 1,200 × (12 − 7) ÷ 12 = +500 lb; mower: 600 × (12 − 13) ÷ 12 = −50 lb
- Tongue weight: 200 + 500 − 50 = 650 lb on a 3,800 lb trailer
- Share: 17.1%, a bit high. Moving the cargo center back about a foot brings it near 12.5%.
How position changes tongue weight
A 1,000 lb load on a 2,000 lb trailer (200 lb empty tongue weight) with the axle 12 ft behind the ball.
| Load distance from ball | Tongue weight | Share | Verdict |
|---|---|---|---|
| 4 ft | 867 lb | 28.9% | Too high |
| 6 ft | 700 lb | 23.3% | Too high |
| 8 ft | 533 lb | 17.8% | Too high |
| 10 ft | 367 lb | 12.2% | In range |
| 12 ft | 200 lb | 6.7% | Too low: sway risk |
| 14 ft | 33 lb | 1.1% | Too low: sway risk |
Balance side to side too
This calculator handles front-to-back balance, which decides tongue weight. Keep the load centered left to right as well: a heavy item on one side overloads that side’s tires and makes the trailer lean in turns. Keep heavy items low, and strap everything so it can’t shift under braking.
Check the result with a real measurement using the tongue weight scale calculator, and compare it with the recommended range in the tongue weight calculator.
Common mistakes
- Loading the heaviest item last, at the back. It ends up behind the axle and lightens the tongue.
- Measuring to the end of the trailer. Positions are from the ball, to the middle of each item.
- Ignoring the empty tongue weight. Even an empty trailer has some; it is the starting point.
- Overcorrecting. Too much weight forward overloads the hitch and the tow vehicle’s rear axle.