205/70R15 vs 225/65R15

225/65R15 is 0.22 in (5.5 mm) taller than 205/70R15, a +0.82% diameter difference. With the speedometer set for 205/70R15, an indicated 60 mph is 60.5 mph on 225/65R15.

Is this a safe swap?

Diameter difference +0.82%: under 1%

By overall diameter alone, 225/65R15 is a near match for 205/70R15; the speedometer changes by less than 1%. 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.

205/70R15 vs 225/65R15 differences
Measurement	205/70R15	225/65R15	Difference	% diff
Overall diameter	26.30 in (668.0 mm)	26.52 in (673.5 mm)	+0.22 in (+5.5 mm)	+0.82%
Sidewall height	5.65 in (143.5 mm)	5.76 in (146.3 mm)	+0.11 in (+2.8 mm)	+1.92%
Section width	8.07 in (205.0 mm)	8.86 in (225.0 mm)	+0.79 in (+20.0 mm)	+9.76%
Circumference	82.62 in (2,098.6 mm)	83.30 in (2,115.9 mm)	+0.68 in (+17.3 mm)	+0.82%
Revolutions per mile	767	761	−6	−0.82%

True speed with the speedometer calibrated for 205/70R15
Indicated	Actual on 205/70R15	Actual on 225/65R15	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.5 mph	+0.5 mph
75 mph	75.0 mph	75.6 mph	+0.6 mph

Ride-height change: 225/65R15 raises the vehicle by 0.11 in (2.8 mm) at the axle (half the +5.5 mm diameter difference).

225/65R15 is 0.22 in taller than 205/70R15 and 20 mm wider, a 0.82% difference in overall diameter.

With the speedometer calibrated for 205/70R15, an indicated 60 mph is actually 60.5 mph on 225/65R15, and revolutions per mile change from 767 to 761.

Both sizes mount on 15-inch wheels.

Size pages

Other comparisons with 205/70R15

Other comparisons with 225/65R15

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