225/70R14 vs 27x8.50R14

27x8.50R14 is 0.60 in (15.2 mm) taller than 225/70R14, a +2.27% diameter difference. With the speedometer set for 225/70R14, an indicated 60 mph is 61.4 mph on 27x8.50R14.

Is this a safe swap?

Diameter difference +2.27%: within the ±3% guideline

By overall diameter alone, 27x8.50R14 falls inside the ±3% range commonly used as a guideline when replacing 225/70R14. 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.

225/70R14 vs 27x8.50R14 differences
Measurement	225/70R14	27x8.50R14	Difference	% diff
Overall diameter	26.40 in (670.6 mm)	27.00 in (685.8 mm)	+0.60 in (+15.2 mm)	+2.27%
Sidewall height	6.20 in (157.5 mm)	6.50 in (165.1 mm)	+0.30 in (+7.6 mm)	+4.83%
Section width	8.86 in (225.0 mm)	8.50 in (215.9 mm)	−0.36 in (−9.1 mm)	−4.04%
Circumference	82.94 in (2,106.8 mm)	84.82 in (2,154.5 mm)	+1.88 in (+47.8 mm)	+2.27%
Revolutions per mile	764	747	−17	−2.22%

True speed with the speedometer calibrated for 225/70R14
Indicated	Actual on 225/70R14	Actual on 27x8.50R14	Difference
30 mph	30.0 mph	30.7 mph	+0.7 mph
60 mph	60.0 mph	61.4 mph	+1.4 mph
75 mph	75.0 mph	76.7 mph	+1.7 mph

Ride-height change: 27x8.50R14 raises the vehicle by 0.30 in (7.6 mm) at the axle (half the +15.2 mm diameter difference).

27x8.50R14 is 0.60 in taller than 225/70R14 and 9 mm narrower, a 2.27% difference in overall diameter.

With the speedometer calibrated for 225/70R14, an indicated 60 mph is actually 61.4 mph on 27x8.50R14, and revolutions per mile change from 764 to 747.

Both sizes mount on 14-inch wheels.

Size pages

Other comparisons with 225/70R14

Other comparisons with 27x8.50R14

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