TireSizesFinder

215/50R15 vs 225/40R16

225/40R16 is 0.38 in (9.6 mm) shorter than 215/50R15, a −1.61% diameter difference. With the speedometer set for 215/50R15, an indicated 60 mph is 59.0 mph on 225/40R16.

Is this a safe swap?

Diameter difference −1.61%: within the ±3% guideline

By overall diameter alone, 225/40R16 falls inside the ±3% range commonly used as a guideline when replacing 215/50R15. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 215/50R15 (23.46 in) vs 225/40R16 (23.09 in)215/50R1523.46 in × 8.46 in225/40R1623.09 in × 8.86 in
Side profile and tread width, drawn to the same scale.
215/50R15 vs 225/40R16 differences
Measurement215/50R15225/40R16Difference% diff
Overall diameter23.46 in (596.0 mm)23.09 in (586.4 mm)−0.38 in (−9.6 mm)−1.61%
Sidewall height4.23 in (107.5 mm)3.54 in (90.0 mm)−0.69 in (−17.5 mm)−16.28%
Section width8.46 in (215.0 mm)8.86 in (225.0 mm)+0.39 in (+10.0 mm)+4.65%
Circumference73.72 in (1,872.4 mm)72.53 in (1,842.2 mm)−1.19 in (−30.2 mm)−1.61%
Revolutions per mile860874+14+1.64%
True speed with the speedometer calibrated for 215/50R15
IndicatedActual on 215/50R15Actual on 225/40R16Difference
30 mph30.0 mph29.5 mph−0.5 mph
60 mph60.0 mph59.0 mph−1.0 mph
75 mph75.0 mph73.8 mph−1.2 mph

Ride-height change: 225/40R16 lowers the vehicle by 0.19 in (4.8 mm) at the axle (half the −9.6 mm diameter difference).

225/40R16 is 0.38 in shorter than 215/50R15 and 10 mm wider, a 1.61% difference in overall diameter.

With the speedometer calibrated for 215/50R15, an indicated 60 mph is actually 59.0 mph on 225/40R16, and revolutions per mile change from 860 to 874.

225/40R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 215/50R15.

Size pages

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