The Wheel & Tire Calculator

Will those wheels fit?

Use our tool to check if your new alloy wheels and tires will fit your vehicle. Enter the wheel and tire sizes to find the perfect fitment and avoid fitment issues such as poke, inset and rubbing. We'll even calculate potential speedo error. Try it now and find your perfect fitment.

Speedo Error
Speedo Reading at 30mph
Speedo reading at 60mph
Ride height change
Arch gap change
Tire fitment
Tire Size205/45R17225/40R18
Wheel Size17 x 7 ET4818 x 8 ET35
Select for Analysis
Wheel 218 x 8 ET35    225/40R18

Wheel size

Wheel diameter value is in Inches, it is the diameter of the wheel without the tire.

Wheel width value is in Inches, it is the width of the section between the mounting flanges on the wheel.

Offset has an ET (Einpress Tiefe) value in millimetres (mm) which indicates the distance between the mounting surface and the geometric centre of the wheel.

Often displayed as:

18 x 8 ET35

Tire size

Tire width value is in millimetres (mm), it is the first value when reading tire size.

Tire Profile value is a percentage of the wheel diameter, typically between 35 and 55 it is the height of the tire sidewall.

Often displayed as:


17 x 7 ET48 205/45R17
18 x 8 ET35 225/40R18

*The strut in diagram is only there for illustrative purposes, real distances will differ so make sure to measure.

Wheel 2 Analysis

0 - Revolutionizing Tire Buying