Tire essentials
How tire size affects ground clearance
An increase in tire diameter does not lift the vehicle by that full amount. The axle rises by the change in radius.
Divide the diameter change by two
Ground-clearance change from nominal tire geometry = (new diameter − old diameter) ÷ 2. If the new tire is 20 mm taller, the theoretical lift is 10 mm. The top of the tire also occupies additional wheel-arch space.
Try the 205 to 215 example
205/55 R16 has a diameter of 631.9 mm. 215/55 R16 has a diameter of 642.9 mm. The 11 mm increase gives a nominal 5.5 mm rise in axle height. It is a modest lift, not an 11 mm increase in clearance.
Distinguish nominal from loaded clearance
A tire deflects under vehicle weight. Actual loaded radius and suspension position affect measured clearance. The lowest point of the vehicle may be a suspension component or body part, and usable clearance varies through suspension travel. Check clearance with the intended load and follow vehicle-specific guidance.
Method and references
Examples use nominal geometry and fixed-price scenarios, with no vehicle-specific specifications implied. See our calculation methodology and editorial policy.
Dimension reference: Tire Rack: calculating tire dimensions. Consult the tire and vehicle manufacturers for actual fitment requirements.