305/25R21 in Inches

A 305/25R21 tire has a 27-inch diameter, a 12-inch width, and is designed for a 21-inch rim.

In high flotation terms, this tire is labeled as 27x12R21.

305/25R21 Tire Size
12"
27"
305/25R21 Tire Size in Inches
305/25R21 Tire Circumference
84.8"
21"
3"
746.9 revs/mile

305/25R21 Tire Overview

Height
27 inches
Wheel Diameter
21 inches
Tire Width
12 inches
Circumference
84.8 inches
Sidewall Height
3 inches
Revolutions
746.9 per mile
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What does 305/25R21 mean?

305/25R21 tire size meaning in inches

305/25R21 is a tire size with the following dimensions:

  • 305 is the width of the tire in millimeters. This number also indicates the appropriate width of the rim on which the tire should be mounted.
  • 25 is the aspect ratio, which is the ratio of the tire's height to its width. This affects the tire's handling and ride comfort
  • R indicates the tire's construction type, meaning it has a radial construction. This provides stability and precision to the tire.
  • 21 is the diameter of the wheel in inches, on which the tire is to be mounted.

305/25R21 Tire Conversion

DimensionsInchesMillimeters
Tire Diameter27 in685.9 mm
Section Width12 in305 mm
Rim Height21 in533 mm
Sidewall Height3 in76.3 mm
Circumference84.8 in2154.8 mm
Revolutions746.9 revs/mile
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FAQ About 305/25R21 Tire

How tall is a 305/25R21 tire?

The height (or diameter) of a 305/25R21 tire is 27 inches

How wide is a 305/25R21 tire?

The width of a 305/25R21 tire is 305 mm, which is about 12 inches.

What size rim fits a 305/25R21 tire?

A 305/25R21 tire fits on a rim that is 21 inches in diameter.

What does the 25 in a 305/25R21 tire mean?

The 25 in a 305/25R21 tire refers to the aspect ratio, meaning the height of the tire's sidewall is 25% of its width.


Alternative Tire Sizes for 305/25R21

Typically, it's recommended to choose a tire with a diameter (height) within 3% of the original equipment manufacturer (OEM) tire size.

However, keep in mind that this is a general guideline and not an absolute rule.

Here are some tire sizes that are compatible with the 305/25R21:

Tire SizeDiameterRim
255/30R2127.0″ (Equal)21 x 8.5-9.5
235/30R2126.6″ (-1.5%)21 x n/a
235/35R2127.5″ (1.9%)21 x n/a
245/30R2126.8″ (-0.7%)21 x 8.0-9.0
245/35R2127.8″ (3.0%)21 x 8.0-9.0
265/30R2127.3″ (1.1%)21 x 9.0-10.0
275/25R2126.4″ (-2.2%)21 x 10
275/30R2127.5″ (1.9%)21 x 9.0-10.0
285/30R2127.7″ (2.6%)21 x 9.5-10.5
295/25R2126.8″ (-0.7%)21 x 10.0-11.0
325/25R2127.4″ (1.5%)21 x 11.5-12.5
375/20R2126.9″ (-0.4%)21 x n/a