Examples
Examples
Try the starting example
- Nominal tire section width (mm)
- 205
- Nominal aspect ratio (%)
- 55
- Nominal rim diameter (inches)
- 16
- Nominal unloaded tire diameter (mm)
- 631.9
- Nominal circular circumference (mm)
- 1,985.172398
- Nominal sidewall height (mm)
- 112.75
- Nominal rim diameter (mm)
- 406.4
- Nominal revolutions per km
- 503.734588
Try another scenario
- Nominal tire section width (mm)
- 225
- Nominal aspect ratio (%)
- 55
- Nominal rim diameter (inches)
- 16
- Nominal unloaded tire diameter (mm)
- 653.9
- Nominal circular circumference (mm)
- 2,054.287436
- Nominal sidewall height (mm)
- 123.75
- Nominal rim diameter (mm)
- 406.4
- Nominal revolutions per km
- 486.786796
Calculation method
Calculation method
Nominal unloaded tire diameter (mm)
Rim inches×25.4+2×section width×aspect/100.
Nominal circular circumference (mm)
pi×nominal diameter, not measured loaded rollout.
Nominal sidewall height (mm)
Width×aspect/100.
Nominal rim diameter (mm)
Inches×25.4 exactly as a unit definition.
Nominal revolutions per km
1,000,000 mm/nominal circumference.
Symbols and units
- a
- Nominal tire section width (mm)
- b
- Nominal aspect ratio (%)
- c
- Nominal rim diameter (inches)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- Nominal sidewall-marking geometry only. Actual loaded rolling circumference, tire construction, rim compatibility and vehicle suitability require measurements/specifications and are not inferred.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
Michelin: nominal tire width, aspect ratio and rim-diameter markings ↗
Background reading; this does not imply endorsement or independent review of SumFizz.