285/40R22 tire size

A 285/40R22 tire is 30.98 inches (786.8 mm) tall, 11.22 in (285 mm) wide and fits a 22-inch wheel. In inch notation it is roughly a 31.0x11.2R22 — a "31-inch" tire.

285/40R22 dimensions
Overall diameter	30.98 in	786.8 mm
Section width	11.22 in	285 mm
Sidewall height	4.49 in	114.0 mm
Circumference	97.32 in	2,472 mm
Revolutions	651.1 per mile	404.6 per km
Rim diameter	22 in	558.8 mm

Compare 285/40R22 with another size

Current size

New size

Speed in mphkm/h

Overall diameter difference

−0.06%

60 mph on the speedometer = 60.0 mph actual

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

Ground clearance: −0.3 mm (−0.01 in)
Revolutions: 651 → 651 per mile

285/40R22 325/35R22

Side-by-side dimensions

	Current	New	Difference	%
Diameter	30.98 in	30.96 in	−0.02 in	−0.06%
Diameter	786.8 mm	786.3 mm	−0.5 mm	−0.06%
Width	11.22 in	12.80 in	+1.57 in	+14.04%
Width	285.0 mm	325.0 mm	+40.0 mm	+14.04%
Sidewall	4.49 in	4.48 in	−0.01 in	−0.22%
Sidewall	114.0 mm	113.8 mm	−0.3 mm	−0.22%
Circumference	97.32 in	97.25 in	−0.06 in	−0.06%
Revs per mile	651.1	651.5	+0.4	+0.06%

Speedometer error

Speedometer shows	Actual speed	Difference
20 mph	20.0 mph	0.0 mph
30 mph	30.0 mph	0.0 mph
40 mph	40.0 mph	0.0 mph
50 mph	50.0 mph	0.0 mph
60 mph	60.0 mph	0.0 mph
70 mph	70.0 mph	0.0 mph
80 mph	79.9 mph	−0.1 mph

Alternative sizes on the same 22-inch wheel

Sizes in use within ±3 % of the overall diameter of 285/40R22:

Plus and minus sizes for 285/40R22

Size	Wheel	Diameter	Difference
255/55R20	Minus 2 (20 in)	31.04 in	+0.22%
275/50R20	Minus 2 (20 in)	30.83 in	−0.48%
285/50R20	Minus 2 (20 in)	31.22 in	+0.79%
295/45R20	Minus 2 (20 in)	30.45 in	−1.69%
315/40R21	Minus 1 (21 in)	30.92 in	−0.18%
255/50R21	Minus 1 (21 in)	31.04 in	+0.20%
285/45R21	Minus 1 (21 in)	31.10 in	+0.39%
275/45R21	Minus 1 (21 in)	30.74 in	−0.75%
255/40R23	Plus 1 (23 in)	31.03 in	+0.18%
285/35R23	Plus 1 (23 in)	30.85 in	−0.39%
295/35R23	Plus 1 (23 in)	31.13 in	+0.50%
325/30R23	Plus 1 (23 in)	30.68 in	−0.97%

Vehicles approved with 285/40R22 tires

Models whose Swiss type approval lists 285/40R22 as a standard or optional size (803 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 22-inch sizes

Reading the 285/40R22 size

285 — section width in millimetres (11.22 in).
40 — aspect ratio: the sidewall is 40 % of the width, 114.0 mm.
R — radial construction (ZR on the sidewall means a high-speed rated radial; the dimensions are the same).
22 — fits a 22-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.