285/35R20 in inches

A 285/35R20 tire is 27.9″ tall and 11.2″ wide, and fits a 20″ wheel. In inches it is written 27.9×11.2R20.

Diameter27.85″

Width11.22″

Sidewall3.93″

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

Manufacturer data

How tall 285/35R20 tires really are

Heights published by BFGoodrich, General, Michelin and Toyo for all 18 tires in this size. Their published revolutions per mile work out to 27.0–27.1″ under load (below).

Real 285/35R20 tires measure 27.87–27.90″, against 27.85″ from the size code. They run both taller and shorter than the size code.

Height under load27.0–27.1″

Published revs per mile (745–746) mean the tire rolls like a 27.0–27.1″ tire on the vehicle. Use this for speedometer calibration.

Weight spread27.5–34.6 lb

The lightest (General G-MAX RS, SL) is 7.1 lb lighter per corner than the heaviest (Toyo Proxes Sport A/S, SL).

18 tires in 285/35R20

Sort by the spec you care about.

	Load					Revs/mi	Source
General G-MAX RSPerformance	SL · 100Y	27.90	27.5	10.0	1,764	746	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 104(Y)	27.90	28.8	9.0	1,984	746	Spec page
Michelin Pilot Sport Cup 2 ConnectPerformance	XL · 104(Y)	27.90	28.8	7.2	1,984	746	Spec page
General G-MAX AS07Performance	XL · 104W	27.90	29.1	10.0	1,984	746	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 104(Y)	27.90	29.2	9.0	1,984	746	Spec page
Michelin Pilot Sport All-Season 4Performance	XL · 104Y	27.90	29.4	10.0	1,984	746	Spec page
Michelin Pilot Sport 4 SPerformance	XL · 104(Y)	27.90	29.9	9.5	1,984	746	Spec page
Toyo Proxes RPerformance	SL · 100(Y)	27.90	29.9	3.7	1,764	745	Spec page
Michelin Pilot Alpin PA4Winter	XL · 104V	27.87	30.0	10.5	1,984	746	Spec page
Michelin Pilot Alpin PA4Winter	XL · 104V	27.87	30.4	10.5	1,984	746	Spec page
Toyo Proxes Sport 2Performance	XL · 104(Y)	27.90	30.4	9.2	1,984	745	Spec page
Toyo Proxes RRPerformance	SL · 100(Y)	27.87	31.5	3.6	1,764	745	Spec page
Michelin Pilot Sport 3Performance	XL · 104(Y)	27.90	32.3	9.5	1,984	746	Spec page
Toyo Proxes R888RPerformance	SL · 100(Y)	27.87	32.6	6.3	1,764	745	Spec page
BFGoodrich g-Force COMP-2 A/S PLUSPerformance	XL · 104Y	27.87	32.7	9.0	1,764	746	Spec page
Toyo Proxes Sport RPerformance	XL · 104W	27.90	33.3	7.2	1,984	745	Spec page
Michelin Pilot Sport 4Performance	XL · 104Y	27.90	34.3	9.5	1,984	746	Spec page
Toyo Proxes Sport A/SPerformance	SL · 100Y	27.87	34.6	9.7	1,764	745	Spec page

Is 285/35R20 a 28-inch tire?

≈28″

Yes. The size code works out to 27.85″, and the 18 tires here publish 27.87–27.90″, so people call it a 28.

All 28-inch tire sizes, on every wheel size.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

Size	Diameter ″	vs 285/35R20	Difference
235/40R20	27.40	-0.45″	-1.6%
315/30R20	27.44	-0.41″	-1.5%
275/35R20	27.58	-0.28″	-1.0%
215/45R20	27.62	-0.24″	-0.8%
325/30R20	27.68	-0.18″	-0.6%
245/40R20	27.72	-0.14″	-0.5%
335/30R20	27.91	+0.06″	+0.2%
255/40R20	28.03	+0.18″	+0.6%
295/35R20	28.13	+0.28″	+1.0%
345/30R20	28.15	+0.30″	+1.1%

How to read 285/35R20

How to read any tire size

How 285/35R20 104Y is printed on the sidewall. It's the most common code among the 18 tires here (6 of them); tires in this size come in other load and speed ratings too.

1285Section width

285 mm across the widest point, or 11.22 inches. Every 285 size

235Aspect ratio

A percentage, not a measurement: the sidewall is 35% as tall as the tire is wide, which is 99.8 mm or 3.93 inches.

3RConstruction

Radial construction.

420Wheel diameter

Mounts on a 20-inch wheel. Approved wheel widths run 9.5″ to 11.0″.

5104Load index

Each tire carries up to 1,984 lb (900 kg) at its maximum pressure.

6YSpeed rating

Rated for up to 186 mph sustained.

XLExtra load

Printed after the size. In this size the XL tires carry up to 1,984 lb each and the standard-load tires up to 1,764 lb, as published.

Specification	Inches	Metric
Overall diameter	27.85	708 mm
Section width	11.22	285 mm
Sidewall height	3.93	99.8 mm
Circumference	87.5	2,223 mm
Revolutions per mile (calculated, unloaded)	724.1	450 per km
Revolutions per mile (published by manufacturers)	745–746	463–464 per km
Approved wheel width	9.5–11.0	241–279 mm

Speedometer error after switching to 285/35R20

Your actual speed– mph

Questions about 285/35R20

What is 285/35R20 in inches?

27.85 inches tall, 11.22 inches wide, on a 20-inch wheel. Written in inches, that is roughly 27.9×11.2R20.

How much does a 285/35R20 tire weigh?

Between 27.5 lb and 34.6 lb for the 18 tires listed here. The lightest is the General G-MAX RS (SL); the heaviest is the Toyo Proxes Sport A/S (SL).

What wheel width do I need for 285/35R20?

Manufacturers approve 9.5–11.0″ wide wheels for this size.

How many revolutions per mile does a 285/35R20 make?

Published figures run 745–746 revolutions per mile. The calculated figure is 724.1, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 285/35R20 than 245/40R20?

0.14 inches taller on paper (27.85″ vs 27.72″), which raises the axle about 0.07″. Your speedometer will read about 0.5% slow.