TireSizesFinder

33x12.50R15 vs 305/70R16

305/70R16 is 0.19 in (4.8 mm) shorter than 33x12.50R15, a −0.57% diameter difference. With the speedometer set for 33x12.50R15, an indicated 60 mph is 59.7 mph on 305/70R16.

Is this a safe swap?

Diameter difference −0.57%: under 1%

By overall diameter alone, 305/70R16 is a near match for 33x12.50R15; 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: 33x12.50R15 (33.00 in) vs 305/70R16 (32.81 in)33x12.50R1533.00 in × 12.50 in305/70R1632.81 in × 12.01 in
Side profile and tread width, drawn to the same scale.
33x12.50R15 vs 305/70R16 differences
Measurement33x12.50R15305/70R16Difference% diff
Overall diameter33.00 in (838.2 mm)32.81 in (833.4 mm)−0.19 in (−4.8 mm)−0.57%
Sidewall height9.00 in (228.6 mm)8.41 in (213.5 mm)−0.59 in (−15.1 mm)−6.61%
Section width12.50 in (317.5 mm)12.01 in (305.0 mm)−0.49 in (−12.5 mm)−3.94%
Circumference103.67 in (2,633.3 mm)103.08 in (2,618.2 mm)−0.59 in (−15.1 mm)−0.57%
Revolutions per mile611615+4+0.58%
True speed with the speedometer calibrated for 33x12.50R15
IndicatedActual on 33x12.50R15Actual on 305/70R16Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.7 mph−0.3 mph
75 mph75.0 mph74.6 mph−0.4 mph

Ride-height change: 305/70R16 lowers the vehicle by 0.09 in (2.4 mm) at the axle (half the −4.8 mm diameter difference).

305/70R16 is 0.19 in shorter than 33x12.50R15 and 13 mm narrower, a 0.57% difference in overall diameter.

With the speedometer calibrated for 33x12.50R15, an indicated 60 mph is actually 59.7 mph on 305/70R16, and revolutions per mile change from 611 to 615.

305/70R16 mounts on a 16-inch wheel, a plus-1 fitment from the 15-inch wheel of 33x12.50R15.

Size pages

Other comparisons with 33x12.50R15

Other comparisons with 305/70R16

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