Tire Size Comparison Tool - Compare Up to Four Tire Sizes

Tires & wheels

Tire size comparison

Compare up to four tire sizes, metric or inch, side by side. Every difference is measured against the tire you mark as the reference, so set that one to your stock size.

Tire sizes

 
 
 
 

Example sizes are loaded. Type over them with your own. Sizes read like 265/70R17, LT285/75R16 or 35x12.50R17. Leave a slot blank to skip it.

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Side view

 

Front view

 

Drawn to scale. The dashed line marks the top of the reference tire.

By the numbers

Specs and speedometer error

Each figure is shown with its difference from the reference tire, which is the highlighted column. The speedometer table assumes the gauge is calibrated for that tire.

Spec sheet

Scroll the table sideways to see every tire

Enter tire sizes above to see the numbers.

Speedometer

Enter two or more sizes to see speedometer error.

 

How these numbers are calculated

Metric sizes

In 265/70R17, 265 is the tread width in millimeters, 70 is the sidewall height as a percent of that width, and 17 is the wheel diameter in inches. Sidewall = width × aspect ratio. Overall diameter = wheel diameter + 2 × sidewall.

Inch sizes

In 35x12.50R17, the three numbers are overall diameter, tread width and wheel diameter, all in inches. The sidewall is half of what is left after the wheel.

Circumference, revs and speed

  • Circumference = π × diameter.
  • Revs per mile = 63,360 ÷ circumference in inches.
  • True speed = speedometer reading × new diameter ÷ reference diameter.
  • Ride height changes by half the difference in diameter.

Nominal figures

These numbers come from the size printed on the sidewall. Real tires run a little different by brand, wheel width, pressure and wear, so measure the actual tire before counting on a tight fit.