How we calculate
Height of the tire sidewall
Tire height without the wheel, calculated as a percentage of tire width. A 205/55 R16 tire has a width of 205 mm, its height is given as the second parameter - in this case 55%, i.e. 112.75 mm.
Overall diameter
The distance from the center of the wheel to the outermost point of the tire, multiplied by two. This is the full height of the tire including the wheel.
Tire circumference
The circumference of the tire is important for determining whether an alternative tire size can be used and whether the given size will fit.
Tire rotations per km
The number of rotations the tire makes every kilometer. Important to know when changing tire size - a difference in rotations results in a speedometer error.