Everyday life

Tire Size Calculator

Find overall tire diameter from its size code.

Parameters Live Compute
Calculated Output
Overall diameter 24.972
Overall diameter 634.3
Sidewall height 101.25
Formula: diameter = rim + 2 × (width × aspect/100)
Step-by-Step Breakdown
1. Values used:
2. Section width = 225
3. Aspect ratio = 45 %
4. Rim diameter = 17
5.
6. Overall diameter = 24.972
7. Overall diameter = 634.3
8. Sidewall height = (225 / 100) x 45 = 2.25 x 45 = 101.25
Did this calculator solve your problem today?
Report issue to loopingon.com
Sponsored

Decode a tire size like 225/45R17 into its real diameter.

The math behind it

sidewall = width × aspect ÷ 100; diameter = rim (×25.4) + 2 × sidewall.

Worked Example

225/45R17 → ~25.0 in diameter.

Frequently Asked Questions

Plus-sizing?

Keep overall diameter similar to avoid speedometer error.

Advertisement