TruckTireGuide.com Semi Truck Tire Reference

Truck Tire Load Ratings

Axle Weight vs Tire Capacity

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A tire capacity check starts with the axle, not the tire catalog. If the loaded axle weight is unknown, the comparison is only a guess.

The example below is intentionally simple and marked example only; real decisions require verified axle weights and official tire data.

This site is for general information only. It does not replace professional tire service, DOT compliance advice, tire manufacturer instructions, vehicle manufacturer recommendations, or fleet policy.

Example only — steer axle

InputExample valueMeaning
Loaded axle weight12,000 lbFrom a scale ticket or documented fleet record
Tires on axle2Single steer axle, one tire per side
Load per tire (rough)6,000 lbAxle weight divided by tire count — not accounting for side-to-side imbalance
Rated capacity per tireConfirm from manufacturer tableDo not use a number from another source

Federal axle weight limits as a reference

Federal highway regulations (23 U.S.C. 127) limit single axles to 20,000 lb and tandem axles to 34,000 lb on Interstate highways. These are road-use limits, not tire capacity limits — both must be respected independently. A tire capacity check compares against the actual loaded weight, not against the legal maximum.

Where errors happen

  • Using empty or unloaded weight instead of the loaded axle weight
  • Ignoring uneven side-to-side loading from cargo placement
  • Using the single-position rating for a tire in dual service
  • Forgetting that GAWR and wheel ratings still apply independently of tire capacity

Capacity Verification Checklist

  • Get the loaded axle weight when practical.
  • Divide by tire count only as a rough screen.
  • Verify official single or dual capacity from manufacturer data.
  • Leave a conservative margin and inspect tire condition.

FAQ

How do I calculate how much load each tire is carrying?

Divide the loaded axle weight by the number of tires on that axle as a rough starting point. For a steer axle with two tires at 12,000 lb, each tire carries approximately 6,000 lb in a balanced scenario. For a tandem drive axle set with eight tires at 34,000 lb combined, each tire carries roughly 4,250 lb in dual service. Side-to-side loading is rarely exactly equal, so treat the division as a conservative screen, not a precise answer.

What should I do if the calculated load per tire exceeds the tire's rated capacity?

Stop and address the situation before continuing to operate. Do not proceed hoping the tire will hold. Either redistribute the cargo, reduce the load, or verify that the correct tire for that axle and load is installed. Overloading a tire generates heat that can cause internal damage or sudden failure without visible warning from outside the tire.

Does GAWR or tire capacity control how much weight can be on an axle?

Both limits apply independently, and the lower one controls. You cannot exceed GAWR because the tires have higher capacity, and you cannot exceed the tires' rated capacity because the axle hardware is rated higher. Both the vehicle certification label (for GAWR) and the tire manufacturer's data (for tire capacity) must be checked separately and both must be within their limits.

Source Notes

References are used for context and verification. Exact tire service decisions should use current manufacturer data, applicable regulations, and qualified inspection.