205/40R17 tire size

A 205/40R17 tire is 23.46 inches (595.8 mm) tall, 8.07 in (205 mm) wide and fits a 17-inch wheel. In inch notation it is roughly a 23.5x8.1R17.

205/40R17 dimensions
Overall diameter	23.46 in	595.8 mm
Section width	8.07 in	205 mm
Sidewall height	3.23 in	82.0 mm
Circumference	73.69 in	1,872 mm
Revolutions	859.8 per mile	534.3 per km
Rim diameter	17 in	431.8 mm

Compare 205/40R17 with another size

Current size

New size

Speed in mphkm/h

Overall diameter difference

+0.42%

60 mph on the speedometer = 60.3 mph actual

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

Ground clearance: +1.3 mm (+0.05 in)
Revolutions: 860 → 856 per mile

205/40R17 185/45R17

Side-by-side dimensions

	Current	New	Difference	%
Diameter	23.46 in	23.56 in	+0.10 in	+0.42%
Diameter	595.8 mm	598.3 mm	+2.5 mm	+0.42%
Width	8.07 in	7.28 in	−0.79 in	−9.76%
Width	205.0 mm	185.0 mm	−20.0 mm	−9.76%
Sidewall	3.23 in	3.28 in	+0.05 in	+1.52%
Sidewall	82.0 mm	83.3 mm	+1.3 mm	+1.52%
Circumference	73.69 in	74.00 in	+0.31 in	+0.42%
Revs per mile	859.8	856.2	−3.6	−0.42%

Speedometer error

Speedometer shows	Actual speed	Difference
20 mph	20.1 mph	+0.1 mph
30 mph	30.1 mph	+0.1 mph
40 mph	40.2 mph	+0.2 mph
50 mph	50.2 mph	+0.2 mph
60 mph	60.3 mph	+0.3 mph
70 mph	70.3 mph	+0.3 mph
80 mph	80.3 mph	+0.3 mph

Alternative sizes on the same 17-inch wheel

Sizes in use within ±3 % of the overall diameter of 205/40R17:

Plus and minus sizes for 205/40R17

Size	Wheel	Diameter	Difference
215/50R15	Minus 2 (15 in)	23.46 in	+0.03%
195/55R15	Minus 2 (15 in)	23.44 in	−0.05%
175/60R15	Minus 2 (15 in)	23.27 in	−0.81%
185/60R15	Minus 2 (15 in)	23.74 in	+1.21%
175/55R16	Minus 1 (16 in)	23.58 in	+0.52%
215/45R16	Minus 1 (16 in)	23.62 in	+0.69%
185/50R16	Minus 1 (16 in)	23.28 in	−0.74%
205/45R16	Minus 1 (16 in)	23.26 in	−0.82%
215/35R18	Plus 1 (18 in)	23.93 in	+2.00%

Vehicles approved with 205/40R17 tires

Models whose Swiss type approval lists 205/40R17 as a standard or optional size (561 approvals in total). Always check your own vehicle's placard or papers.

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 17-inch sizes

Reading the 205/40R17 size

205 — section width in millimetres (8.07 in).
40 — aspect ratio: the sidewall is 40 % of the width, 82.0 mm.
R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
17 — fits a 17-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.