tireheight.com

285/25R20 in inches

A 285/25R20 tire is 25.6″ tall and 11.2″ wide, and fits a 20″ wheel. In inches it is written 25.6×11.2R20.

Diameter25.61″
Width11.22″
Sidewall2.81″
285/25R20 drawn to scale: 25.61 inch diameter, 2.81 inch sidewall, 20 inch wheel, 11.22 inch tread width20″ wheel2.81″25.61″ overall11.22″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 285/25R20 tires really are

Heights published by Michelin for the one tire in this size. Their published revolutions per mile work out to 24.8″ under load (below).

The one tire listed, the Michelin Pilot Sport 4 S, measures 25.60″: 0.01″ shorter than the size code's 25.61″.

Height under load24.8″

Published revs per mile (813) mean the tire rolls like a 24.8″ tire on the vehicle. Use this for speedometer calibration.

1 tire in 285/25R20

Sort by the spec you care about.

LoadRevs/miSource
Michelin Pilot Sport 4 SPerformanceXL · 93(Y)25.6026.99.51,433813Spec page

Is 285/25R20 a 26-inch tire?

≈26″

Close. The size code works out to 25.61″, and the 1 tire here publishes 25.60″, so people call it a 26.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 285/25R20Difference
225/30R2025.31-0.30″-1.2%
275/30R1925.50-0.11″-0.4%
235/30R2025.55-0.06″-0.2%
245/30R2025.79+0.18″+0.7%
295/25R2025.81+0.20″+0.8%
305/25R2026.00+0.39″+1.5%
255/30R2026.02+0.41″+1.6%
225/35R2026.20+0.59″+2.3%
265/30R2026.26+0.65″+2.5%
325/25R2026.40+0.79″+3.1%

How to read 285/25R20

How to read any tire size

285/25R20 93Y as printed on the tire sidewall, with each part numbered285/25R20 93Y123456
How 285/25R20 93Y is printed on the sidewall. It's the most common code among the 1 tire here; 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

225Aspect ratio

A percentage, not a measurement: the sidewall is 25% as tall as the tire is wide, which is 71.3 mm or 2.81 inches.

3RConstruction

Radial construction.

420Wheel diameter

Mounts on a 20-inch wheel. Approved wheel widths run 10.5″ to 10.5″.

593Load index

Each tire carries up to 1,433 lb (650 kg) at its maximum pressure.

6YSpeed rating

Rated for up to 186 mph sustained.

XLExtra load

Printed after the size.

SpecificationInchesMetric
Overall diameter25.61651 mm
Section width11.22285 mm
Sidewall height2.8171.3 mm
Circumference80.52,044 mm
Revolutions per mile (calculated, unloaded)787.5489 per km
Revolutions per mile (published by manufacturers)813505 per km
Approved wheel width10.5267 mm

Speedometer error after switching to 285/25R20

Your actual speed– mph

Questions about 285/25R20

What is 285/25R20 in inches?

25.61 inches tall, 11.22 inches wide, on a 20-inch wheel. Written in inches, that is roughly 25.6×11.2R20.

What wheel width do I need for 285/25R20?

Manufacturers approve 10.5″ wide wheels for this size.

How many revolutions per mile does a 285/25R20 make?

Published figures run 813 revolutions per mile. The calculated figure is 787.5, but manufacturers measure the tire under load, where it rolls on a smaller radius.

How much taller is 285/25R20 than 235/30R20?

0.06 inches taller on paper (25.61″ vs 25.55″), which raises the axle about 0.03″. Your speedometer will read about 0.2% slow.