Tire Size Inches

Tire size converter

Enter a metric tire size and read its diameter, section width, sidewall and revolutions per mile in both inches and millimetres.

Enter a tire size

mm

%

in

What it measures

34.07 in

Overall diameter
34.07 in / 865.5 mm
Section width
10.83 in / 275 mm
Sidewall height
7.04 in / 178.8 mm
Circumference
107.05 in / 2,719.0 mm
Revolutions per mile
591.9 per mile / 367.8 per km

Popular sizes

Popular sizes
Size Overall diameter Section width
275/65R20 in inches 34.07 10.83
275/60R20 tire size 32.99 10.83
275/70R18 in inches 33.16 10.83
285/70R17 tire size 32.71 11.22
the 315/70R17 size page 34.36 12.40
265/70R17 31.61 10.43
275/55R20 tire size 31.91 10.83
the 305/55R20 size page 33.21 12.01
275/65R18 dimensions 32.07 10.83
285/60R20 dimensions 33.46 11.22
how big 285/75R16 is 32.83 11.22
295/65R20 in inches 35.10 11.61
285/55R20 32.34 11.22
how big 235/75R15 is 28.88 9.25
255/75R17 32.06 10.04

How this is worked out

sidewall height in millimetres = section width × aspect ratio ÷ 100

overall diameter in inches = wheel diameter + (section width × aspect ratio × 2) ÷ 2540

section width in inches = section width in millimetres ÷ 25.4

circumference in inches = π × overall diameter

revolutions per mile = 63360 ÷ circumference in inches

The divisor is 2540, not the 2550 some converters publish. Two sidewalls in inches are 2 × width × aspect ÷ (100 × 25.4), and the rounding costs about 0.07 inches at 34 inches.