275/65R20 tire size

A 275/65R20 tire is 34.07 inches (865.5 mm) tall, 10.83 in (275 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 34.1x10.8R20 — a "34-inch" tire.

275/65R20 dimensions
Overall diameter	34.07 in	865.5 mm
Section width	10.83 in	275 mm
Sidewall height	7.04 in	178.8 mm
Circumference	107.05 in	2,719 mm
Revolutions	591.9 per mile	367.8 per km
Rim diameter	20 in	508.0 mm

Compare 275/65R20 with another size

Current size

New size

Speed in mphkm/h

Overall diameter difference

−1.79%

60 mph on the speedometer = 58.9 mph actual

Within the ±3 % diameter range most tire fitters accept.

Ground clearance: −7.8 mm (−0.31 in)
Revolutions: 592 → 603 per mile

275/65R20 285/60R20

Side-by-side dimensions

	Current	New	Difference	%
Diameter	34.07 in	33.46 in	−0.61 in	−1.79%
Diameter	865.5 mm	850.0 mm	−15.5 mm	−1.79%
Width	10.83 in	11.22 in	+0.39 in	+3.64%
Width	275.0 mm	285.0 mm	+10.0 mm	+3.64%
Sidewall	7.04 in	6.73 in	−0.31 in	−4.34%
Sidewall	178.8 mm	171.0 mm	−7.8 mm	−4.34%
Circumference	107.05 in	105.13 in	−1.92 in	−1.79%
Revs per mile	591.9	602.7	+10.8	+1.82%

Speedometer error

Speedometer shows	Actual speed	Difference
20 mph	19.6 mph	−0.4 mph
30 mph	29.5 mph	−0.5 mph
40 mph	39.3 mph	−0.7 mph
50 mph	49.1 mph	−0.9 mph
60 mph	58.9 mph	−1.1 mph
70 mph	68.7 mph	−1.3 mph
80 mph	78.6 mph	−1.4 mph

Alternative sizes on the same 20-inch wheel

Sizes in use within ±3 % of the overall diameter of 275/65R20:

Plus and minus sizes for 275/65R20

Size	Wheel	Diameter	Difference
275/70R18	Minus 2 (18 in)	33.16 in	−2.69%

Nearby 20-inch sizes

Reading the 275/65R20 size

275 — section width in millimetres (10.83 in).
65 — aspect ratio: the sidewall is 65 % of the width, 178.8 mm.
R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
20 — fits a 20-inch diameter wheel.

The load index and speed rating (for example 91V) follow the size on the sidewall. They must meet at least the values on your vehicle's tire placard.