Tire size comparison

Enter two tire sizes (e.g. 205/55 R16 and 225/45 R17): calculate diameters, circumference and percentage difference.

Tire 1 · width

aspect %

rim "

Tire 2 · width

aspect %

rim "

What it's for

Changing tire size changes the wheel's overall diameter: this affects the speed shown by the speedometer and the odometer's km. Here you see the percentage difference.

Rule of thumb

To avoid throwing off the speedometer, the diameter difference should stay within ±2-3%. A larger tire makes the speedometer read below the real speed.