225/55R15 tire size

A 225/55R15 tire is 24.74 inches (628.5 mm) tall, 8.86 in (225 mm) wide and fits a 15-inch wheel. In inch notation it is roughly a 24.7x8.9R15.

225/55R15 dimensions
Overall diameter	24.74 in	628.5 mm
Section width	8.86 in	225 mm
Sidewall height	4.87 in	123.8 mm
Circumference	77.74 in	1,974 mm
Revolutions	815.1 per mile	506.5 per km
Rim diameter	15 in	381.0 mm

Compare 225/55R15 with another size

Current size

New size

Speed in mphkm/h

Overall diameter difference

−0.24%

60 mph on the speedometer = 59.9 mph actual

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

Ground clearance: −0.8 mm (−0.03 in)
Revolutions: 815 → 817 per mile

225/55R15 205/60R15

Side-by-side dimensions

	Current	New	Difference	%
Diameter	24.74 in	24.69 in	−0.06 in	−0.24%
Diameter	628.5 mm	627.0 mm	−1.5 mm	−0.24%
Width	8.86 in	8.07 in	−0.79 in	−8.89%
Width	225.0 mm	205.0 mm	−20.0 mm	−8.89%
Sidewall	4.87 in	4.84 in	−0.03 in	−0.61%
Sidewall	123.8 mm	123.0 mm	−0.8 mm	−0.61%
Circumference	77.74 in	77.55 in	−0.19 in	−0.24%
Revs per mile	815.1	817.0	+1.9	+0.24%

Speedometer error

Speedometer shows	Actual speed	Difference
20 mph	20.0 mph	0.0 mph
30 mph	29.9 mph	−0.1 mph
40 mph	39.9 mph	−0.1 mph
50 mph	49.9 mph	−0.1 mph
60 mph	59.9 mph	−0.1 mph
70 mph	69.8 mph	−0.2 mph
80 mph	79.8 mph	−0.2 mph

Alternative sizes on the same 15-inch wheel

Sizes in use within ±3 % of the overall diameter of 225/55R15:

Plus and minus sizes for 225/55R15

Size	Wheel	Diameter	Difference
195/70R14	Minus 1 (14 in)	24.75 in	+0.02%
205/70R14	Minus 1 (14 in)	25.30 in	+2.24%
245/45R16	Plus 1 (16 in)	24.68 in	−0.25%
225/50R16	Plus 1 (16 in)	24.86 in	+0.46%
205/55R16	Plus 1 (16 in)	24.88 in	+0.54%
215/50R16	Plus 1 (16 in)	24.46 in	−1.13%
245/40R17	Plus 2 (17 in)	24.72 in	−0.11%
215/45R17	Plus 2 (17 in)	24.62 in	−0.51%
225/45R17	Plus 2 (17 in)	24.97 in	+0.92%
255/40R17	Plus 2 (17 in)	25.03 in	+1.16%
245/35R18	Plus 3 (18 in)	24.75 in	+0.03%
215/40R18	Plus 3 (18 in)	24.77 in	+0.11%
235/35R18	Plus 3 (18 in)	24.48 in	−1.08%
255/35R18	Plus 3 (18 in)	25.03 in	+1.15%

Vehicles approved with 225/55R15 tires

Models whose Swiss type approval lists 225/55R15 as a standard or optional size (31 approvals in total). Always check your own vehicle's placard or papers.

BMW Z3

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 15-inch sizes

Reading the 225/55R15 size

225 — section width in millimetres (8.86 in).
55 — aspect ratio: the sidewall is 55 % of the width, 123.8 mm.
R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
15 — fits a 15-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.