235/55R20 in inches

A 235/55R20 tire is 30.2″ tall and 9.3″ wide, and fits a 20″ wheel. In inches it is written 30.2×9.3R20.

Diameter30.18″

Width9.25″

Sidewall5.09″

Drawn to scale. Nominal dimensions calculated from the size code.

Manufacturer data

How tall 235/55R20 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 23 tires in this size. Their published revolutions per mile work out to 29.2–29.3″ under load (below).

Real 235/55R20 tires measure 30.10–30.20″, against 30.18″ from the size code. They run both taller and shorter than the size code.

Height under load29.2–29.3″

Published revs per mile (688–690) mean the tire rolls like a 29.2–29.3″ tire on the vehicle. Use this for speedometer calibration.

Weight spread28.0–34.8 lb

The lightest (General AltiMAX365 AW, SL) is 6.8 lb lighter per corner than the heaviest (General Grabber H/T, SL).

23 tires in 235/55R20

Sort by the spec you care about.

	Load					Revs/mi	Source
General AltiMAX365 AWTouring	SL · 102V	30.20	28.0	11.0	1,874	688	Spec page
Michelin Premier LTXAll-season	SL · 102V	30.10	28.2	8.5	1,874	690	Spec page
General AltiMAX RT45Touring	SL · 102H	30.20	29.0	11.0	1,874	688	Spec page
General Grabber H/THighway	SL · 102V	30.20	29.3	11.0	1,874	688	Spec page
Michelin CrossClimate2All-season	SL · 102V	30.10	29.3	10.0	1,874	690	Spec page
Michelin Pilot Sport EVPerformance	XL · 105Y	30.20	29.3	8.5	2,039	690	Spec page
Michelin Primacy Tour A/STouring	SL · 102H	30.20	29.4	9.5	1,874	690	Spec page
Michelin Pilot Sport All-Season 4Performance	XL · 105V	30.20	30.0	9.0	2,039	690	Spec page
Michelin Pilot Alpin 5Winter	XL · 105V	30.16	30.3	10.5	2,039	690	Spec page
Michelin Defender2All-season	SL · 102H	30.10	31.3	10.5	1,874	690	Spec page
Michelin X-Ice Snow+Winter	XL · 105H	30.16	31.7	10.5	2,039	690	Spec page
BFGoodrich Advantage ControlAll-season	SL · 102H	30.16	31.9	11.5	1,874	690	Spec page
General AltiMAX Arctic XWinter	XL · 105T	30.20	31.9	12.0	2,039	688	Spec page
Toyo Extensa A/S IIAll-season	SL · 102V	30.16	32.1	10.7	1,874	689	Spec page
Toyo Celsius SportPerformance	SL · 102V	30.16	32.3	10.5	1,874	689	Spec page
Michelin X-Ice SnowWinter	XL · 105H	30.16	32.4	10.5	2,039	690	Spec page
Toyo Proxes G-Tour	SL · 102V	30.20	32.4	11.8	1,874	689	Spec page
BFGoodrich Advantage ControlAll-season	SL · 102V	30.16	32.6	10.5	1,874	690	Spec page
Toyo Celsius IITouring	XL · 105H	30.16	33.5	11.6	2,039	689	Spec page
Toyo Observe G3-IceWinter	XL · 105T	30.16	33.5	11.3	2,039	689	Spec page
Toyo Proxes ST IIIPerformance	XL · 105V	30.16	34.0	10.1	2,039	689	Spec page
Toyo OPEN COUNTRY Q/TAll-season	SL · 102V	30.16	34.7	12.5	1,874	689	Spec page
General Grabber H/THighway	SL · 102H	30.20	34.8	12.0	1,874	688	Spec page

Is 235/55R20 a 30-inch tire?

≈30″

Yes. The size code works out to 30.18″, and the 23 tires here publish 30.10–30.20″, so people call it a 30.

All 30-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 235/55R20	Difference
265/45R20	29.39	-0.79″	-2.6%
305/40R20	29.61	-0.57″	-1.9%
245/50R20	29.65	-0.53″	-1.8%
275/45R20	29.74	-0.43″	-1.4%
255/50R20	30.04	-0.14″	-0.5%
285/45R20	30.10	-0.08″	-0.3%
265/50R20	30.43	+0.26″	+0.8%
295/45R20	30.45	+0.28″	+0.9%
305/45R20	30.81	+0.63″	+2.1%
275/50R20	30.83	+0.65″	+2.2%

How to read 235/55R20

How to read any tire size

How 235/55R20 102V is printed on the sidewall. It's the most common code among the 23 tires here (9 of them); tires in this size come in other load and speed ratings too.

1235Section width

235 mm across the widest point, or 9.25 inches. Every 235 size

255Aspect ratio

A percentage, not a measurement: the sidewall is 55% as tall as the tire is wide, which is 129.3 mm or 5.09 inches.

3RConstruction

Radial construction.

420Wheel diameter

Mounts on a 20-inch wheel. Approved wheel widths run 6.5″ to 8.5″.

5102Load index

Each tire carries up to 1,874 lb (850 kg) at its maximum pressure.

6VSpeed rating

Rated for up to 149 mph sustained.

Specification	Inches	Metric
Overall diameter	30.18	767 mm
Section width	9.25	235 mm
Sidewall height	5.09	129.3 mm
Circumference	94.8	2,408 mm
Revolutions per mile (calculated, unloaded)	668.3	415 per km
Revolutions per mile (published by manufacturers)	688–690	428–429 per km
Approved wheel width	6.5–8.5	165–216 mm

Speedometer error after switching to 235/55R20

Your actual speed– mph

Questions about 235/55R20

What is 235/55R20 in inches?

30.18 inches tall, 9.25 inches wide, on a 20-inch wheel. Written in inches, that is roughly 30.2×9.3R20.

How much does a 235/55R20 tire weigh?

Between 28.0 lb and 34.8 lb for the 23 tires listed here. The lightest is the General AltiMAX365 AW (SL); the heaviest is the General Grabber H/T (SL).

What wheel width do I need for 235/55R20?

Manufacturers approve 6.5–8.5″ wide wheels for this size.

How many revolutions per mile does a 235/55R20 make?

Published figures run 688–690 revolutions per mile. The calculated figure is 668.3, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 235/55R20 than 285/45R20?

0.08 inches taller on paper (30.18″ vs 30.10″), which raises the axle about 0.04″. Your speedometer will read about 0.3% slow.