tireheight.com

225/30R20 in inches

A 225/30R20 tire is 25.3″ tall and 8.9″ wide, and fits a 20″ wheel. In inches it is written 25.3×8.9R20.

Diameter25.31″
Width8.86″
Sidewall2.66″
225/30R20 drawn to scale: 25.31 inch diameter, 2.66 inch sidewall, 20 inch wheel, 8.86 inch tread width20″ wheel2.66″25.31″ overall8.86″ wideSide view
Drawn to scale. Nominal dimensions calculated from the size code.
Manufacturer data

How tall 225/30R20 tires really are

Heights published by Toyo for the one tire in this size. Their published revolutions per mile work out to 24.6″ under load (below).

The one tire listed, the Toyo Proxes Sport A/S, measures 25.35″: 0.04″ taller than the size code's 25.31″.

Height under load24.6″

Published revs per mile (819) mean the tire rolls like a 24.6″ tire on the vehicle. Use this for speedometer calibration.

1 tire in 225/30R20

Sort by the spec you care about.

LoadRevs/miSource
Toyo Proxes Sport A/SPerformanceXL · 85W25.3522.19.31,135819Spec page

Is 225/30R20 a 25-inch tire?

≈25″

Close. The size code works out to 25.31″, and the 1 tire here publishes 25.35″, so people call it a 25.

Compare with nearby sizes

Differences in overall diameter, calculated from each size code.

SizeDiameter ″vs 225/30R20Difference
225/35R1925.20-0.11″-0.5%
265/30R1925.26-0.06″-0.2%
235/35R1925.48+0.16″+0.6%
235/30R2025.55+0.24″+0.9%
285/25R2025.61+0.30″+1.2%
245/30R2025.79+0.47″+1.9%
295/25R2025.81+0.49″+1.9%
305/25R2026.00+0.69″+2.7%
255/30R2026.02+0.71″+2.8%
225/35R2026.20+0.89″+3.5%

How to read 225/30R20

How to read any tire size

225/30R20 85W as printed on the tire sidewall, with each part numbered225/30R20 85W123456
How 225/30R20 85W 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.
1225Section width

225 mm across the widest point, or 8.86 inches. Every 225 size

230Aspect ratio

A percentage, not a measurement: the sidewall is 30% as tall as the tire is wide, which is 67.5 mm or 2.66 inches.

3RConstruction

Radial construction.

420Wheel diameter

Mounts on a 20-inch wheel. Approved wheel widths run 8.0″ to 8.0″.

585Load index

Each tire carries up to 1,135 lb (515 kg) at its maximum pressure.

6WSpeed rating

Rated for up to 168 mph sustained.

XLExtra load

Printed after the size.

SpecificationInchesMetric
Overall diameter25.31643 mm
Section width8.86225 mm
Sidewall height2.6667.5 mm
Circumference79.52,020 mm
Revolutions per mile (calculated, unloaded)796.7495 per km
Revolutions per mile (published by manufacturers)819509 per km
Approved wheel width8.0203 mm

Speedometer error after switching to 225/30R20

Your actual speed– mph

Questions about 225/30R20

What is 225/30R20 in inches?

25.31 inches tall, 8.86 inches wide, on a 20-inch wheel. Written in inches, that is roughly 25.3×8.9R20.

What wheel width do I need for 225/30R20?

Manufacturers approve 8.0″ wide wheels for this size.

How many revolutions per mile does a 225/30R20 make?

Published figures run 819 revolutions per mile. The calculated figure is 796.7, but manufacturers measure the tire under load, where it rolls on a smaller radius.