225/60R16 vs 235/55R17
Switching from 225/60R16 to 235/55R17 changes the overall diameter by +13.9 mm (+2.1%) — inside the commonly used ±3% guideline. Every figure below is calculated from the two size codes with the standard formulas.
| Measurement | 225/60R16 | 235/55R17 | Difference |
|---|---|---|---|
| Overall diameter | 676.4 mm | 690.3 mm | +13.9 mm (+2.1%) |
| Overall diameter | 26.63 in | 27.18 in | +0.55 in |
| Tire width | 225 mm (8.86 in) | 235 mm (9.25 in) | +10 mm |
| Sidewall height | 135.0 mm (5.31 in) | 129.3 mm (5.09 in) | -5.8 mm |
| Wheel (rim) diameter | 16.0 in | 17.0 in | +1.0 in |
| Circumference | 2125 mm | 2169 mm | +44 mm |
| Revolutions per mile | 2379 | 2331 | -48 |
| Revolutions per km | 471 | 461 | -9 |
Speedometer error
Calibrated for 225/60R16, the speedometer under-reads or over-reads once 235/55R17 is fitted. This is your real speed at each indicated speed:
| Speedometer shows | Actual speed on 235/55R17 | Error |
|---|---|---|
| 20 mph | 20.4 mph | +0.4 mph |
| 40 mph | 40.8 mph | +0.8 mph |
| 60 mph | 61.2 mph | +1.2 mph |
| 80 mph | 81.6 mph | +1.6 mph |
| 100 mph | 102.1 mph | +2.1 mph |
How these two sizes are worked out
225/60R16 breaks down as a 225 mm tread width with a sidewall of 60% of that width (135.0 mm) on a 16.0-inch wheel, giving an overall diameter of 676.4 mm (26.63 in). 235/55R17 works out to 690.3 mm (27.18 in) the same way. The standard formulas are the same ones used on the tire size calculator page: diameter = rim × 25.4 + 2 × sidewall, circumference = π × diameter, revolutions per mile = 63,360 ÷ diameter in inches.
Nominal sizes vary slightly between brands and models, and tread wear shrinks a tire over its life. These figures follow the size codes exactly; your vehicle manual or a professional tire shop is the authority for what fits your vehicle.
More comparisons
Frequently asked questions
Can I replace 225/60R16 tires with 235/55R17?
The diameter change is +2.1%, which is within the commonly used ±3% guideline. Diameter is only one part of fitment — wheel width range, load index, speed rating and physical clearance all have to check out too, so confirm with your vehicle manual or a professional tire shop before buying.
Will 235/55R17 make my speedometer read wrong?
Yes, by the diameter ratio. When the dial shows 60 mph you are really doing 61.2 mph on 235/55R17. The full table above covers 20 to 100 mph.
Which tire is taller, 225/60R16 or 235/55R17?
235/55R17 is taller — 690.3 mm against 676.4 mm overall diameter, a difference of 13.9 mm.