CALCULATOR
Tire Size Calculator
Decode a tire size into diameter, sidewall and circumference.
Your results
724.3 mm
Overall diameter · 225/65 R17
Calculate to see all six dimensions.
How the calculation works
Sidewall height = width × aspect ratio ÷ 100. Wheel diameter = rim diameter × 25.4. Overall diameter = wheel diameter + 2 × sidewall height. Circumference = π × overall diameter.
With circumference in millimetres, revolutions per kilometre = 1,000,000 ÷ circumference. Revolutions per mile = 1,609,344 ÷ circumference.
These are nominal, unloaded dimensions. Actual rolling circumference varies with tire construction, wear, load and inflation. A similar diameter does not guarantee safe fitment or legal approval. Confirm manufacturer-approved sizes, load and speed ratings, wheel compatibility and clearance.