TireSizesFinder

215/45R18 vs 275/30R19

275/30R19 is 0.12 in (3.1 mm) shorter than 215/45R18, a −0.48% diameter difference. With the speedometer set for 215/45R18, an indicated 60 mph is 59.7 mph on 275/30R19.

Is this a safe swap?

Diameter difference −0.48%: under 1%

By overall diameter alone, 275/30R19 is a near match for 215/45R18; 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: 215/45R18 (25.62 in) vs 275/30R19 (25.50 in)215/45R1825.62 in × 8.46 in275/30R1925.50 in × 10.83 in
Side profile and tread width, drawn to the same scale.
215/45R18 vs 275/30R19 differences
Measurement215/45R18275/30R19Difference% diff
Overall diameter25.62 in (650.7 mm)25.50 in (647.6 mm)−0.12 in (−3.1 mm)−0.48%
Sidewall height3.81 in (96.8 mm)3.25 in (82.5 mm)−0.56 in (−14.2 mm)−14.73%
Section width8.46 in (215.0 mm)10.83 in (275.0 mm)+2.36 in (+60.0 mm)+27.91%
Circumference80.48 in (2,044.2 mm)80.10 in (2,034.5 mm)−0.38 in (−9.7 mm)−0.48%
Revolutions per mile787791+4+0.48%
True speed with the speedometer calibrated for 215/45R18
IndicatedActual on 215/45R18Actual on 275/30R19Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.7 mph−0.3 mph
75 mph75.0 mph74.6 mph−0.4 mph

Ride-height change: 275/30R19 lowers the vehicle by 0.06 in (1.6 mm) at the axle (half the −3.1 mm diameter difference).

275/30R19 is 0.12 in shorter than 215/45R18 and 60 mm wider, a 0.48% difference in overall diameter.

With the speedometer calibrated for 215/45R18, an indicated 60 mph is actually 59.7 mph on 275/30R19, and revolutions per mile change from 787 to 791.

275/30R19 mounts on a 19-inch wheel, a plus-1 fitment from the 18-inch wheel of 215/45R18.

Size pages

Other comparisons with 215/45R18

Other comparisons with 275/30R19

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