155/60R20 tire size

A 155/60R20 tire is 27.32 inches (694.0 mm) tall, 6.10 in (155 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 27.3x6.1R20.

155/60R20 dimensions
Overall diameter	27.32 in	694.0 mm
Section width	6.10 in	155 mm
Sidewall height	3.66 in	93.0 mm
Circumference	85.84 in	2,180 mm
Revolutions	738.1 per mile	458.7 per km
Rim diameter	20 in	508.0 mm

Compare 155/60R20 with another size

Current size

New size

Speed in mphkm/h

Overall diameter difference

+0.94%

60 mph on the speedometer = 60.6 mph actual

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

Ground clearance: +3.3 mm (+0.13 in)
Revolutions: 738 → 731 per mile

155/60R20 175/55R20

Side-by-side dimensions

	Current	New	Difference	%
Diameter	27.32 in	27.58 in	+0.26 in	+0.94%
Diameter	694.0 mm	700.5 mm	+6.5 mm	+0.94%
Width	6.10 in	6.89 in	+0.79 in	+12.90%
Width	155.0 mm	175.0 mm	+20.0 mm	+12.90%
Sidewall	3.66 in	3.79 in	+0.13 in	+3.49%
Sidewall	93.0 mm	96.3 mm	+3.3 mm	+3.49%
Circumference	85.84 in	86.64 in	+0.80 in	+0.94%
Revs per mile	738.1	731.3	−6.8	−0.93%

Speedometer error

Speedometer shows	Actual speed	Difference
20 mph	20.2 mph	+0.2 mph
30 mph	30.3 mph	+0.3 mph
40 mph	40.4 mph	+0.4 mph
50 mph	50.5 mph	+0.5 mph
60 mph	60.6 mph	+0.6 mph
70 mph	70.7 mph	+0.7 mph
80 mph	80.7 mph	+0.7 mph

Alternative sizes on the same 20-inch wheel

Sizes in use within ±3 % of the overall diameter of 155/60R20:

Plus and minus sizes for 155/60R20

Size	Wheel	Diameter	Difference
195/60R18	Minus 2 (18 in)	27.21 in	−0.40%
205/60R18	Minus 2 (18 in)	27.69 in	+1.33%
205/55R18	Minus 2 (18 in)	26.88 in	−1.63%
175/60R19	Minus 1 (19 in)	27.27 in	−0.20%
195/55R19	Minus 1 (19 in)	27.44 in	+0.45%
155/70R19	Minus 1 (19 in)	27.54 in	+0.81%
205/50R19	Minus 1 (19 in)	27.07 in	−0.92%

Vehicles approved with 155/60R20 tires

Models whose Swiss type approval lists 155/60R20 as a standard or optional size (21 approvals in total). Always check your own vehicle's placard or papers.

BMW i3

Source: Swiss Federal Roads Office (FEDRO/ASTRA), open government data. Original data (downloaded 2026-09-29). Data processed by us; errors in processing are ours, not the publisher's.

Nearby 20-inch sizes

175/55R20 (+0.9%)

Reading the 155/60R20 size

155 — section width in millimetres (6.10 in).
60 — aspect ratio: the sidewall is 60 % of the width, 93.0 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.