Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Outer diameter
28.52
inches
Sidewall height
5.76
inches
Circumference
89.6
inches
Revolutions per mile
707
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter section width (mm).
- 2Enter aspect ratio (%).
- 3Enter rim diameter (in).
- 4Read your outer diameter on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Convert a P-metric tire code (e.g. 225/65R17) into physical dimensions.