265/40R17 vs 215/50R17

215/50R17 is 0.12 in (3.0 mm) taller than 265/40R17, a +0.47% diameter difference. With the speedometer set for 265/40R17, an indicated 60 mph is 60.3 mph on 215/50R17.

Is this a safe swap?

Diameter difference +0.47%: under 1%

By overall diameter alone, 215/50R17 is a near match for 265/40R17; 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.

265/40R17 vs 215/50R17 differences
Measurement	265/40R17	215/50R17	Difference	% diff
Overall diameter	25.35 in (643.8 mm)	25.46 in (646.8 mm)	+0.12 in (+3.0 mm)	+0.47%
Sidewall height	4.17 in (106.0 mm)	4.23 in (107.5 mm)	+0.06 in (+1.5 mm)	+1.42%
Section width	10.43 in (265.0 mm)	8.46 in (215.0 mm)	−1.97 in (−50.0 mm)	−18.87%
Circumference	79.63 in (2,022.6 mm)	80.00 in (2,032.0 mm)	+0.37 in (+9.4 mm)	+0.47%
Revolutions per mile	796	792	−4	−0.46%

True speed with the speedometer calibrated for 265/40R17
Indicated	Actual on 265/40R17	Actual on 215/50R17	Difference
30 mph	30.0 mph	30.1 mph	+0.1 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.3 mph	+0.3 mph

Ride-height change: 215/50R17 raises the vehicle by 0.06 in (1.5 mm) at the axle (half the +3.0 mm diameter difference).

215/50R17 is 0.12 in taller than 265/40R17 and 50 mm narrower, a 0.47% difference in overall diameter.

With the speedometer calibrated for 265/40R17, an indicated 60 mph is actually 60.3 mph on 215/50R17, and revolutions per mile change from 796 to 792.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 265/40R17

Other comparisons with 215/50R17

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