Tire & Wheel Calculators
Tire Size Tools

Tire Size Calculator

Tire Size Calculator. Decode, calculate and compare nominal tire dimensions. Calculations run in your browser; entered tire and wheel values are not uploaded.

Inputs
{{/each}}
Calculations run in your browser; entered tire and wheel values are not uploaded.
ⓘCalculated dimensions are nominal values based on tire-size notation; actual measured dimensions vary. These calculators compare nominal tire and wheel geometry. Actual fitment depends on the vehicle, wheel, tire model, suspension, brake clearance, load/speed ratings and local requirements. Verify final fitment before purchase or installation.

Formula & method

Sidewall = width × aspect ratio; diameter = rim × 25.4 + 2 × sidewall; circumference = π × diameter.

Example

225/45R17 → 634.3 mm (24.97 in) nominal diameter.

Limitations

Calculated dimensions are nominal values based on tire-size notation; actual measured dimensions vary. These calculators compare nominal tire and wheel geometry. Actual fitment depends on the vehicle, wheel, tire model, suspension, brake clearance, load/speed ratings and local requirements. Verify final fitment before purchase or installation.