Tire Tools & Calculators

GVWR + axles + hitch type → the per-tire capacity and load index you need, with the 20% heat reserve.

Compare two sizes: diameter, sidewall, revs per mile, speedometer error — with a visual.

How to measure lug patterns (even and 5-lug), an exact calculator, and the standard trailer patterns.

33X12.50R20 in metric? Real dimensions plus the closest standard equivalents on your rim.

Price ÷ tread life — the number fleets buy on. Compare two tires and see the annual fleet impact.

How old are your tires? Decode the sidewall date stamp and get industry age guidance.

Bigger tires? See your new cruise RPM, effective gearing, and the re-gear that restores stock feel.

Convert between the two wheel-fitment numbers with a live cross-section diagram.

Penny test, quarter test, and a live gauge showing exactly how much usable tread is left.

How much PSI the cold takes away — real gas-law math with a seasonal table.

Front/rear fitment checker plus the factory staggered sizes on popular performance cars.