27x8.50R14 vs 225/75R14

225/75R14 is 0.29 in (7.3 mm) taller than 27x8.50R14, a +1.06% diameter difference. With the speedometer set for 27x8.50R14, an indicated 60 mph is 60.6 mph on 225/75R14.

Is this a safe swap?

Diameter difference +1.06%: within the ±3% guideline

By overall diameter alone, 225/75R14 falls inside the ±3% range commonly used as a guideline when replacing 27x8.50R14. 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.

27x8.50R14 vs 225/75R14 differences
Measurement	27x8.50R14	225/75R14	Difference	% diff
Overall diameter	27.00 in (685.8 mm)	27.29 in (693.1 mm)	+0.29 in (+7.3 mm)	+1.06%
Sidewall height	6.50 in (165.1 mm)	6.64 in (168.8 mm)	+0.14 in (+3.7 mm)	+2.21%
Section width	8.50 in (215.9 mm)	8.86 in (225.0 mm)	+0.36 in (+9.1 mm)	+4.21%
Circumference	84.82 in (2,154.5 mm)	85.73 in (2,177.4 mm)	+0.90 in (+22.9 mm)	+1.06%
Revolutions per mile	747	739	−8	−1.05%

True speed with the speedometer calibrated for 27x8.50R14
Indicated	Actual on 27x8.50R14	Actual on 225/75R14	Difference
30 mph	30.0 mph	30.3 mph	+0.3 mph
60 mph	60.0 mph	60.6 mph	+0.6 mph
75 mph	75.0 mph	75.8 mph	+0.8 mph

Ride-height change: 225/75R14 raises the vehicle by 0.14 in (3.6 mm) at the axle (half the +7.3 mm diameter difference).

225/75R14 is 0.29 in taller than 27x8.50R14 and 9 mm wider, a 1.06% difference in overall diameter.

With the speedometer calibrated for 27x8.50R14, an indicated 60 mph is actually 60.6 mph on 225/75R14, and revolutions per mile change from 747 to 739.

Both sizes mount on 14-inch wheels.

Size pages

Other comparisons with 27x8.50R14

Other comparisons with 225/75R14

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