245/65R16 vs 255/65R16

255/65R16 is 0.51 in (13.0 mm) taller than 245/65R16, a +1.79% diameter difference. With the speedometer set for 245/65R16, an indicated 60 mph is 61.1 mph on 255/65R16.

Is this a safe swap?

Diameter difference +1.79%: within the ±3% guideline

By overall diameter alone, 255/65R16 falls inside the ±3% range commonly used as a guideline when replacing 245/65R16. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

245/65R16 vs 255/65R16 differences
Measurement	245/65R16	255/65R16	Difference	% diff
Overall diameter	28.54 in (724.9 mm)	29.05 in (737.9 mm)	+0.51 in (+13.0 mm)	+1.79%
Sidewall height	6.27 in (159.3 mm)	6.53 in (165.8 mm)	+0.26 in (+6.5 mm)	+4.08%
Section width	9.65 in (245.0 mm)	10.04 in (255.0 mm)	+0.39 in (+10.0 mm)	+4.08%
Circumference	89.66 in (2,277.3 mm)	91.27 in (2,318.2 mm)	+1.61 in (+40.8 mm)	+1.79%
Revolutions per mile	707	694	−12	−1.76%

True speed with the speedometer calibrated for 245/65R16
Indicated	Actual on 245/65R16	Actual on 255/65R16	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	61.1 mph	+1.1 mph
75 mph	75.0 mph	76.3 mph	+1.3 mph

Ride-height change: 255/65R16 raises the vehicle by 0.26 in (6.5 mm) at the axle (half the +13.0 mm diameter difference).

255/65R16 is 0.51 in taller than 245/65R16 and 10 mm wider, a 1.79% difference in overall diameter.

With the speedometer calibrated for 245/65R16, an indicated 60 mph is actually 61.1 mph on 255/65R16, and revolutions per mile change from 707 to 694.

Both sizes mount on 16-inch wheels.

Size pages

Other comparisons with 245/65R16

Other comparisons with 255/65R16

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.