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.
cm mm | Wheel 1 | Wheel 2 |
|---|---|---|
| Diameter | 626.1 mm | 640.1 mm |
| Circumference | 1967 mm | 2010.9 mm |
| Poke | 40.9 mm | 66.6 mm |
| Inset | 136.9 mm | 136.6 mm |
| Speedo Error | 0% | -2.24% |
| Speedo Reading at 30mph | 30 | 29.3 |
| Speedo reading at 60mph | 60 | 58.7 |
| Ride height change | 0 mm | 7 mm |
| Arch gap change | 0 mm | -7 mm |
| Tire fitment | Ideal size | Ideal size |
| Tire Size | 205/45R17 | 225/40R18 |
| Wheel Size | 17 x 7 ET48 | 18 x 8 ET35 |
| Select for Analysis |
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:
17 x 7 ET48
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:
205/45R17
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:
225/40R18
*The strut in diagram is only there for illustrative purposes, real distances will differ so make sure to measure.
Wheel 2 Analysis
- Wheel 2's overall diameter (including the tire) is 14 mm bigger than Wheel 1.
- Wheel 2's face will poke out 25.7 mm more than Wheel 1.
- Wheel 2 has an inner rim which is 0.3 mm further away from suspension strut than Wheel 1.