255/65R16 vs 225/75R16

225/75R16 is 0.24 in (6.0 mm) taller than 255/65R16, a +0.81% diameter difference. With the speedometer set for 255/65R16, an indicated 60 mph is 60.5 mph on 225/75R16.

Is this a safe swap?

Diameter difference +0.81%: under 1%

By overall diameter alone, 225/75R16 is a near match for 255/65R16; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 255/65R16 (29.05 in) vs 225/75R16 (29.29 in)255/65R1629.05 in × 10.04 in225/75R1629.29 in × 8.86 in
Side profile and tread width, drawn to the same scale.
255/65R16 vs 225/75R16 differences
Measurement255/65R16225/75R16Difference% diff
Overall diameter29.05 in (737.9 mm)29.29 in (743.9 mm)+0.24 in (+6.0 mm)+0.81%
Sidewall height6.53 in (165.8 mm)6.64 in (168.8 mm)+0.12 in (+3.0 mm)+1.81%
Section width10.04 in (255.0 mm)8.86 in (225.0 mm)−1.18 in (−30.0 mm)−11.76%
Circumference91.27 in (2,318.2 mm)92.01 in (2,337.0 mm)+0.74 in (+18.8 mm)+0.81%
Revolutions per mile694689−6−0.81%
True speed with the speedometer calibrated for 255/65R16
IndicatedActual on 255/65R16Actual on 225/75R16Difference
30 mph30.0 mph30.2 mph+0.2 mph
60 mph60.0 mph60.5 mph+0.5 mph
75 mph75.0 mph75.6 mph+0.6 mph

Ride-height change: 225/75R16 raises the vehicle by 0.12 in (3.0 mm) at the axle (half the +6.0 mm diameter difference).

225/75R16 is 0.24 in taller than 255/65R16 and 30 mm narrower, a 0.81% difference in overall diameter.

With the speedometer calibrated for 255/65R16, an indicated 60 mph is actually 60.5 mph on 225/75R16, and revolutions per mile change from 694 to 689.

Both sizes mount on 16-inch wheels.

Size pages

Other comparisons with 255/65R16

Other comparisons with 225/75R16

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.