TireSizesFinder

37x12.50R20 vs 37x13.50R20

37x13.50R20 is 0.00 in (0.0 mm) taller than 37x12.50R20, a 0.00% diameter difference. With the speedometer set for 37x12.50R20, an indicated 60 mph is 60.0 mph on 37x13.50R20.

Is this a safe swap?

Diameter difference 0.00%: under 1%

By overall diameter alone, 37x13.50R20 is a near match for 37x12.50R20; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 37x12.50R20 (37.00 in) vs 37x13.50R20 (37.00 in)37x12.50R2037.00 in × 12.50 in37x13.50R2037.00 in × 13.50 in
Side profile and tread width, drawn to the same scale.
37x12.50R20 vs 37x13.50R20 differences
Measurement37x12.50R2037x13.50R20Difference% diff
Overall diameter37.00 in (939.8 mm)37.00 in (939.8 mm)0.00 in (0.0 mm)0.00%
Sidewall height8.50 in (215.9 mm)8.50 in (215.9 mm)0.00 in (0.0 mm)0.00%
Section width12.50 in (317.5 mm)13.50 in (342.9 mm)+1.00 in (+25.4 mm)+8.00%
Circumference116.24 in (2,952.5 mm)116.24 in (2,952.5 mm)0.00 in (0.0 mm)0.00%
Revolutions per mile54554500.00%
True speed with the speedometer calibrated for 37x12.50R20
IndicatedActual on 37x12.50R20Actual on 37x13.50R20Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.0 mph0.0 mph
75 mph75.0 mph75.0 mph0.0 mph

Ride-height change: 37x13.50R20 does not change the vehicle at the axle (half the 0.0 mm diameter difference).

37x13.50R20 is the same height as 37x12.50R20 and 25 mm wider, a 0.00% difference in overall diameter.

With the speedometer calibrated for 37x12.50R20, an indicated 60 mph is actually 60.0 mph on 37x13.50R20, and revolutions per mile change from 545 to 545.

Both sizes mount on 20-inch wheels.

Size pages

Other comparisons with 37x12.50R20

Other comparisons with 37x13.50R20

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