Wheel Offset to Backspace Calculator
Well after you found you perfect set of rims you find that the number has an 'offset' instead of a 'backspace'
number. It's easy to convert from one to the other so you can get the correct fitment for your wheels. Typically
Backspace is measured in inches (in) and offset measured in Millimeters (mm). If you need to convert from
To Find the the backspace given the offset and rims tire size use this formula:
Backspace = (Rim's Tire Width + 1)/2 + (Offset/25.4)
Rim's Tire Width = Specified Tire Mounting Width for the rim, NOT the total
rim width. The common practice is to add 1" to this, and the calculations
above has it as well.
Offset = The rims given Offset in Millimeters
Backspace = The results in inches
CALCULATOR IS BELOW THE CUTAWAY IMAGE OF THE RIM