175/65R14 vs 225/40R16

225/40R16 is 0.13 in (3.3 mm) taller than 175/65R14, a +0.57% diameter difference. With the speedometer set for 175/65R14, an indicated 60 mph is 60.3 mph on 225/40R16.

Is this a safe swap?

Diameter difference +0.57%: under 1%

By overall diameter alone, 225/40R16 is a near match for 175/65R14; 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.

175/65R14 vs 225/40R16 differences
Measurement	175/65R14	225/40R16	Difference	% diff
Overall diameter	22.96 in (583.1 mm)	23.09 in (586.4 mm)	+0.13 in (+3.3 mm)	+0.57%
Sidewall height	4.48 in (113.8 mm)	3.54 in (90.0 mm)	−0.94 in (−23.7 mm)	−20.88%
Section width	6.89 in (175.0 mm)	8.86 in (225.0 mm)	+1.97 in (+50.0 mm)	+28.57%
Circumference	72.12 in (1,831.9 mm)	72.53 in (1,842.2 mm)	+0.41 in (+10.4 mm)	+0.57%
Revolutions per mile	879	874	−5	−0.56%

True speed with the speedometer calibrated for 175/65R14
Indicated	Actual on 175/65R14	Actual on 225/40R16	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.3 mph	+0.3 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 225/40R16 raises the vehicle by 0.06 in (1.7 mm) at the axle (half the +3.3 mm diameter difference).

225/40R16 is 0.13 in taller than 175/65R14 and 50 mm wider, a 0.57% difference in overall diameter.

With the speedometer calibrated for 175/65R14, an indicated 60 mph is actually 60.3 mph on 225/40R16, and revolutions per mile change from 879 to 874.

225/40R16 mounts on a 16-inch wheel, a plus-2 fitment from the 14-inch wheel of 175/65R14.

Size pages

Other comparisons with 175/65R14

Other comparisons with 225/40R16

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