Trailer load placement calculator

How load placement sets tongue weight

A trailer balances on its axle like a seesaw. The further forward you put the weight, the more of it presses down on the coupler as tongue weight. Put it right over the axle and it adds no tongue weight at all; put it behind the axle and it actually lifts the tongue — the setup that causes dangerous sway. The physics is a simple moment balance:

tongue weight = trailer weight × (coupler-to-axle − load position) ÷ coupler-to-axle

That's why two trailers of identical weight can have wildly different tongue weights: it's all in the packing.

The 60/40 loading rule

The practical shortcut hitch makers and U-Haul teach is to load roughly 60% of the cargo weight ahead of the axle and 40% behind. On most trailers that lands tongue weight in the 10–15% range automatically. Keep the heaviest items low and over or just ahead of the axle, and strap everything down so it can't shift on the road and change your tongue weight mid-trip.

Reading the result

• Under 10% — too light. Slide the load forward.
• 10–15% — the target zone for conventional bumper-pull trailers.
• Over 15% — too heavy on the tongue. Slide the load rearward.
• Negative — the load is behind the axle and the tongue is lifting. Fix this before towing.

This tool predicts tongue weight from geometry; once you're packed,measure the real value, check it in thetongue weight calculator, and read up onwhat causes trailer sway.