285/75R16 vs 33x12.50R15
A calculated comparison of tire dimensions, speedometer change and clearance.
Last checked 12 October 2026Published by Sidewall GuideFormulas follow the Tire and Rim Association and ETRTO size conventions
Within 3%: a common safe change
A similar diameter does not confirm fitment. Check load index, wheel width and clearance.
| Dimension | Current | New | Difference |
|---|---|---|---|
| Overall diameter | 32.83 in (834 mm) | 33.00 in (838 mm) | +0.17 in (+0.5%) |
| Section width | 11.22 in (285 mm) | 12.50 in (318 mm) | +1.28 in (+11.4%) |
| Sidewall height | 8.42 in (214 mm) | 9.00 in (229 mm) | +0.58 in (+6.9%) |
| Circumference | 103.14 in (2,620 mm) | 103.67 in (2,633 mm) | +0.53 in (+0.5%) |
| Revolutions per mile | 614 | 611 | −3 (−0.5%) |
Your speedometer
When your speedometer reads 30 / 45 / 60 / 75 mph, you are really doing …
| Speedometer reads | You are really doing |
|---|---|
| 30 mph | 30.2 mph |
| 45 mph | 45.2 mph |
| 60 mph | 60.3 mph |
| 75 mph | 75.4 mph |
Your speedometer will read low: you are going faster than it shows.
Your odometer will count 1,000 miles when you have driven 1,005 miles.
Clearance
Ride height: +0.08 in
Tread edge: +0.64 in further out and +0.64 in further in, on the same wheel offset
Ride height is half the diameter change. The width change splits equally to each side of the tire.
Fitment
Can I fit 33x12.50R15 instead of 285/75R16?
The calculated overall diameter changes by 0.17 in (0.5%). That is within 3%, a common size-change guideline. This calculation cannot confirm fitment for a specific vehicle.
Plus-sizing
Other sizes near 285/75R16
Common sizes on the same wheel and on +1 and +2 wheels whose overall diameter stays within 3% of 285/75R16's 32.83 in.
Next step
Compare your own sizes
Use the calculator with both sizes prefilled, then change either value to match your vehicle or replacement tire.
Compare your own sizes