Tire Spec 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.
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
Service type
P-metric passenger car
Construction
Radial
Load index
97
Maximum load per tire
730 kg
Maximum load per tire
1,609 lb
Speed symbol
H
Speed rating
210 km/h
Speed rating
130.5 mph
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

6 steps
  1. Decoded "P225/60R16 97H": section width 225 mm, aspect ratio 60%, rim 16 in.
  2. Sidewall height h = 225 x 60 / 100 = 135 mm.
  3. Overall diameter d = 16 x 25.4 + 2 x 135 = 676.4 mm.
  4. Circumference c = pi x 676.4 = 2124.9733 mm.
  5. Revolutions per mile = 1,609,344 / 2124.9733 = 757.348.
  6. Service description 97H: load index 97 = 730 kg per tire, speed symbol H = 210 km/h.

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