RV and Trailer Calculators
Trailer tire load.
Enter the loaded trailer weight, the tongue weight and the maximum load printed on your tire, and see the average load per tire and how close it is to the rating. Runs in your browser; nothing is sent or stored.
Inputs
Result
Fill the form and press Calculate.
Load per tire = (loaded trailer weight - tongue weight) / number of tires. A 7,000 lb trailer with 12% tongue weight on 4 tires averages 1,540 lb per tire, 72% of a 2,150 lb tire rating.
Worked example
Loaded weight 7,000 lb, 12% tongue weight = 840 lb carried by the tow vehicle. The tires carry 6,160 lb; over 4 tires that is 1,540 lb per tire. Against a 2,150 lb tire rating that is 71.6%, with 2,440 lb of total margin across the four tires.
How it works
Load per tire = (loaded weight - tongue weight) / tires. The tow vehicle carries the tongue weight, so only the rest sits on the trailer's tires. The result is an average. A lopsided load, a leaning trailer or a heavier curb side can put more on one tire than the average, and a tire's load capacity depends on its inflation pressure: load and inflation tables are used together, and the sidewall maximum applies at the maximum cold pressure printed there.
The 85 percent "tight" line is a common rule of thumb, not a published standard. If you are near or over it, weigh each wheel position on a scale, use tires with a higher load rating, or lighten the load.
Sources opened 2026-10-08: Tire code - Wikipedia. Planning aid only, not professional, engineering or safety advice. Your vehicle, trailer, tire, battery and boat manuals and the weight labels on your equipment come first; when in doubt, weigh it or ask a qualified professional.
FAQ
How much weight can a trailer tire carry?
It is printed on the sidewall as the maximum load, and it applies at the maximum cold inflation pressure shown there. This tool compares your calculated load with that number.
Do trailer tires carry the tongue weight?
No. The tow vehicle carries the tongue weight, so the trailer tires carry the loaded weight minus the tongue weight.
Is the average load per tire enough?
It is a starting point. Loads are rarely even, so a scale check at each wheel position is better, especially for lopsided loads.
What if my tires are close to the limit?
Reduce the load, move to tires with a higher load rating that fit your wheels and axle, and check the pressure is set to the value the load requires.
Does tire pressure change load capacity?
Yes. Load capacity depends on inflation pressure, which is why load and inflation tables are used together. Underinflated tires carry less.