Tire size calculator
Check how a different tire width, aspect ratio, or wheel diameter changes overall diameter.
How to use these estimates
Enter your own numbers and compare scenarios. Taxes, insurance, loan fees, driving conditions, and local labor rates can change the actual amount.
How tire diameter is calculated
Overall diameter in inches = wheel diameter + 2 × tire width in millimeters × aspect ratio ÷ 100 ÷ 25.4. The percentage change compares new diameter with current diameter.
Example and limitations
If the new diameter is larger, the vehicle travels farther per wheel revolution. This is only a geometric estimate; clearance, load rating, wheel fit, and vehicle systems still need checking.
Explore the calculators
Use the tabs above to open a dedicated page for each estimate. Enter numbers from your vehicle, loan offer, or repair quote.
Built for real decisions
Check the assumptions below each result and compare more than one scenario. These estimates are a starting point, not a price quote.