Type the size on your sidewall today and the size you are thinking of buying. See the real speed behind the dashboard number, the odometer drift, and whether the swap stays inside the legal speedometer limit.
All values calculated from the size codes. Real tires vary by brand, wear, pressure and load.
Drag to set the distance your odometer shows. The odometer counts wheel turns, so a larger tire covers more road per turn.
Uses the error box above (0 means exact today). The rule check compares the dashboard to the true speed.
The legal limits apply to a vehicle as type approved. Most cars read a little high from the factory, so a swap that makes the speedometer read low is the one to avoid. Tire sizes also have to fit your wheel arches and load rating, which this page cannot check.