Size Tire Calculator

The first number in the code: 225 in 225/60R16.
Sidewall height as a percentage of section width: 60 in 225/60R16.
The wheel diameter in inches: 16 in 225/60R16.
Optional. Enter the whole sidewall designation and it overrides the three fields above, and decodes the load index and speed symbol.
Comparison only. Leave at 0 to compare against the tire entered above.
Leave at 0 for a single-tire calculation with no comparison.
Used to show what the new tire is really doing when the dial reads this figure.
Overall diameter
676.40 mm
Tire Size Calculator
Tire size
225/60R16
Sidewall height
135.00 mm
Sidewall height
5.315 in
Overall diameter
26.630 in
Section width
8.858 in
Circumference
2,124.97 mm
Circumference
83.660 in
Revolutions per mile
757.35 rev/mi
Revolutions per kilometre
470.59 rev/km
Original tire diameter
676.40 mm
Worked out from NHTSA, Tire terminology and size designation and 4 other sources.
These are nominal dimensions derived from the size code. A mounted tire measures slightly differently depending on rim width, inflation pressure, load and wear.

How this is worked out

4 steps
  1. Sidewall height h = 225 x 60 / 100 = 135 mm.
  2. Overall diameter d = 16 x 25.4 + 2 x 135 = 676.4 mm.
  3. Circumference c = pi x 676.4 = 2124.9733 mm.
  4. Revolutions per mile = 1,609,344 / 2124.9733 = 757.348.

Results are general information, not financial, tax, legal, medical or engineering advice.