Trailer Weight Distribution Calculator
Find the trailer tongue weight and its percentage of loaded trailer weight, and see whether your cargo sits far enough forward of the axle for stable towing.
How it works
Tongue % = tongue weight ÷ loaded trailer weight × 100 · Target = 10–15% of GTW
A conventional (bumper-pull) trailer tows stably only when 10–15% of its loaded weight presses down on the hitch ball. Too little tongue weight lets the trailer fishtail because its mass is behind the axle acting like a pendulum; too much overloads the tow vehicle’s rear axle and lifts weight off the front, dulling steering and braking. The fix is almost always where the cargo sits — moving heavy items forward of the axle raises tongue weight, moving them back lowers it.
Worked example
A trailer that grosses 5,000 lb should carry 500–750 lb on the tongue. A measured 550 lb is 550 ÷ 5,000 = 11% — comfortably inside the 10–15% window, with the remaining 4,450 lb riding on the trailer’s own axles.
Frequently asked questions
What percentage should trailer tongue weight be?
For a standard bumper-pull trailer, 10–15% of the loaded trailer weight should rest on the tongue. Fifth-wheels and gooseneck trailers use a higher 15–25% pin weight because the load sits over the tow vehicle’s axle instead of behind it.
What happens if the tongue weight is too low?
The trailer becomes prone to sway. With too little weight ahead of the axle the trailer swings side to side at speed, and a gust or truck pass can start an oscillation that is hard to recover. Shifting cargo forward of the axle usually cures it.
How do I measure tongue weight?
Use a dedicated tongue-weight scale under the coupler, or a bathroom-scale-and-lever method for lighter trailers. Weigh the trailer fully loaded the way you will actually tow it, since a shifted or half-empty load changes the number.
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This calculator is for educational purposes. Double-check important results before acting on them.