235/35R20 tire size

A 235/35R20 tire is 26.48 inches (672.5 mm) tall, 9.25 in (235 mm) wide and fits a 20-inch wheel. In inch notation it is roughly a 26.5x9.3R20.

235/35R20 dimensions
Overall diameter	26.48 in	672.5 mm
Section width	9.25 in	235 mm
Sidewall height	3.24 in	82.3 mm
Circumference	83.18 in	2,113 mm
Revolutions	761.7 per mile	473.3 per km
Rim diameter	20 in	508.0 mm

Compare 235/35R20 with another size

Current size

New size

Speed in mphkm/h

Overall diameter difference

+0.07%

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: 762 → 761 per mile

235/35R20 275/30R20

Side-by-side dimensions

	Current	New	Difference	%
Diameter	26.48 in	26.50 in	+0.02 in	+0.07%
Diameter	672.5 mm	673.0 mm	+0.5 mm	+0.07%
Width	9.25 in	10.83 in	+1.57 in	+17.02%
Width	235.0 mm	275.0 mm	+40.0 mm	+17.02%
Sidewall	3.24 in	3.25 in	+0.01 in	+0.30%
Sidewall	82.3 mm	82.5 mm	+0.3 mm	+0.30%
Circumference	83.18 in	83.24 in	+0.06 in	+0.07%
Revs per mile	761.7	761.2	−0.6	−0.07%

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	70.1 mph	+0.1 mph
80 mph	80.1 mph	+0.1 mph

Alternative sizes on the same 20-inch wheel

Sizes in use within ±3 % of the overall diameter of 235/35R20:

Plus and minus sizes for 235/35R20

Size	Wheel	Diameter	Difference
215/50R18	Minus 2 (18 in)	26.46 in	−0.04%
265/40R18	Minus 2 (18 in)	26.35 in	−0.49%
235/45R18	Minus 2 (18 in)	26.33 in	−0.57%
275/40R18	Minus 2 (18 in)	26.66 in	+0.70%
235/40R19	Minus 1 (19 in)	26.40 in	−0.28%
275/35R19	Minus 1 (19 in)	26.58 in	+0.39%
265/35R19	Minus 1 (19 in)	26.30 in	−0.65%
245/40R19	Minus 1 (19 in)	26.72 in	+0.91%
265/30R21	Plus 1 (21 in)	27.26 in	+2.96%

Vehicles approved with 235/35R20 tires

Models whose Swiss type approval lists 235/35R20 as a standard or optional size (344 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 20-inch sizes

Reading the 235/35R20 size

235 — section width in millimetres (9.25 in).
35 — aspect ratio: the sidewall is 35 % of the width, 82.3 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.