175/60R15 vs 225/40R16

225/40R16 is 0.18 in (4.6 mm) shorter than 175/60R15, a −0.78% diameter difference. With the speedometer set for 175/60R15, an indicated 60 mph is 59.5 mph on 225/40R16.

Is this a safe swap?

Diameter difference −0.78%: under 1%

By overall diameter alone, 225/40R16 is a near match for 175/60R15; 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: 175/60R15 (23.27 in) vs 225/40R16 (23.09 in)175/60R1523.27 in × 6.89 in225/40R1623.09 in × 8.86 in
Side profile and tread width, drawn to the same scale.
175/60R15 vs 225/40R16 differences
Measurement175/60R15225/40R16Difference% diff
Overall diameter23.27 in (591.0 mm)23.09 in (586.4 mm)−0.18 in (−4.6 mm)−0.78%
Sidewall height4.13 in (105.0 mm)3.54 in (90.0 mm)−0.59 in (−15.0 mm)−14.29%
Section width6.89 in (175.0 mm)8.86 in (225.0 mm)+1.97 in (+50.0 mm)+28.57%
Circumference73.10 in (1,856.7 mm)72.53 in (1,842.2 mm)−0.57 in (−14.5 mm)−0.78%
Revolutions per mile867874+7+0.78%
True speed with the speedometer calibrated for 175/60R15
IndicatedActual on 175/60R15Actual on 225/40R16Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 225/40R16 lowers the vehicle by 0.09 in (2.3 mm) at the axle (half the −4.6 mm diameter difference).

225/40R16 is 0.18 in shorter than 175/60R15 and 50 mm wider, a 0.78% difference in overall diameter.

With the speedometer calibrated for 175/60R15, an indicated 60 mph is actually 59.5 mph on 225/40R16, and revolutions per mile change from 867 to 874.

225/40R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 175/60R15.

Size pages

Other comparisons with 175/60R15

Other comparisons with 225/40R16

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