TireSizesFinder

275/65R20 vs 35x12.50R20

35x12.50R20 is 0.93 in (23.5 mm) taller than 275/65R20, a +2.72% diameter difference. With the speedometer set for 275/65R20, an indicated 60 mph is 61.6 mph on 35x12.50R20.

Is this a safe swap?

Diameter difference +2.72%: within the ±3% guideline

By overall diameter alone, 35x12.50R20 falls inside the ±3% range commonly used as a guideline when replacing 275/65R20. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 275/65R20 (34.07 in) vs 35x12.50R20 (35.00 in)275/65R2034.07 in × 10.83 in35x12.50R2035.00 in × 12.50 in
Side profile and tread width, drawn to the same scale.
275/65R20 vs 35x12.50R20 differences
Measurement275/65R2035x12.50R20Difference% diff
Overall diameter34.07 in (865.5 mm)35.00 in (889.0 mm)+0.93 in (+23.5 mm)+2.72%
Sidewall height7.04 in (178.8 mm)7.50 in (190.5 mm)+0.46 in (+11.8 mm)+6.57%
Section width10.83 in (275.0 mm)12.50 in (317.5 mm)+1.67 in (+42.5 mm)+15.45%
Circumference107.05 in (2,719.0 mm)109.96 in (2,792.9 mm)+2.91 in (+73.8 mm)+2.72%
Revolutions per mile592576−16−2.64%
True speed with the speedometer calibrated for 275/65R20
IndicatedActual on 275/65R20Actual on 35x12.50R20Difference
30 mph30.0 mph30.8 mph+0.8 mph
60 mph60.0 mph61.6 mph+1.6 mph
75 mph75.0 mph77.0 mph+2.0 mph

Ride-height change: 35x12.50R20 raises the vehicle by 0.46 in (11.8 mm) at the axle (half the +23.5 mm diameter difference).

35x12.50R20 is 0.93 in taller than 275/65R20 and 43 mm wider, a 2.72% difference in overall diameter.

With the speedometer calibrated for 275/65R20, an indicated 60 mph is actually 61.6 mph on 35x12.50R20, and revolutions per mile change from 592 to 576.

Both sizes mount on 20-inch wheels.

Size pages

Other comparisons with 275/65R20

Other comparisons with 35x12.50R20

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