Tire Size Comparison Calculator

Compare two tire sizes — see diameter difference, speedometer error, and ground clearance change.

Original Tire Size (e.g. 225/65R17)

New Tire Size (e.g. 235/70R17)

Measurement	Original	New	Difference

What the numbers mean:

225 = section width in mm, 65 = aspect ratio (sidewall height as % of width), R17 = rim diameter in inches
Speedometer error: positive = speedometer reads faster than actual; negative = reads slower
Stay within ±3% diameter change to avoid affecting ABS, odometer accuracy, and speedometer
Larger tires may also require clearance checks in wheel wells