245/40R21 In Inches – Tire Size & Rim Fitment Guide


What size tire is 245/40R21 in Inches?

The 245/40R21 tire has an overall diameter of 28.7 inches, a section width of 9.6 inches, and can be mounted on 21 x 8.0-9.5 inches rim. The equivalent tire size in the high flotation system is 28.7x9.6R21.

InchesMillimeters
Tire Diameter28.7729.4
Section Width9.6245
Rim Height21533
Sidewall Height3.998
Circumference90.22291.5
tire diameter
9.6"
28.7"
Tire Side
Tire Circumference
90.2"
21"
3.9"
702.3 Revs/Mile

To make it clear, we'll break down each part of the 245/40R21 tire size to know what these numbers represent & how they may affect your vehicle tire's performance:



How tall is a 245/40R21 tire?

A 245/40R21 tire has a height of 28.7 inches (729.4 mm). This is the measurement from the bottom to the highest point at the top of a tire through its exact center when inflated and no load.

Tire Diameter
Tire diameter: 28.7 In.


How wide is a 245/40R21 tire?

The 245/40R21 has a width of 9.6 inches (245 mm). This is the tire measurement at its thickest point, the distance between the inner sidewall’s and the outer sidewall’s widest point, also known as section width or tread width.

tread width
Tread width: 9.6 In.


245/40R21 sidewall height

The sidewall height of a 245/40R21 is 3.9 inches (98 mm). It’s measured from the rim to the outer edge of the tire's tread, expressed as a percentage of tire width.

sidewall height
Sidewall height: 3.9 In.


What size rim do I need for 245/40R21 tire?

You can put on a rim with a height of 21 inches and a rim width ranging from 8.0-9.5 inches for a 245/40R21 tire. (Based on recommendations of The Tire and Rim Association (TRA))

Putting very wide tires on narrow rims or vice versa can result in reduced performance of the tire.

Rim Diameter
Rim height: 21 In.
rim width
Rim width: 8.0-9.5 In.


245/40R21 circumference

The 245/40R21 tire has a circumference of 90.2 inches (2291.5 mm), This is the measurement of the distance the tire covers in one full rotation.

The tire circumference is important for your vehicle's overall performance, affecting its speedometer accuracy, acceleration & fuel efficiency.

Circumference
Circumference: 90.2 In.


245/40R21 Revolutions

The 245/40R21 performs 702.3 revs/mile. Revolutions per mile indicate the number of times a tire rotates while it covers the distance of one mile.

Revolutions
702.3 revs/mile


Alternative Tire Sizes for 245/40R21

As a rule, you can replace the tire within a 3% difference in tire diameter (height) of the OEM tire size. Here is the full list of replacement sizes compatible with 245/40R21:

Tire SizeDiameterRim (H x W)
265/45R2029.4″ (+2.4%)20″ x 8.5-10.0″
305/35R2129.4″ (+2.4%)21″ x 10.0-12.0″
315/30R2229.4″ (+2.4%)22″ x 10.5-11.5″
275/25R2429.4″ (+2.4%)24″ x 9.5-10.0″
235/50R2029.3″ (+2%)20″ x 6.5-8.5″
295/40R2029.3″ (+2%)20″ x 10.0-11.5″
235/45R2129.3″ (+2%)21″ x 7.5-9.0″
265/40R2129.3″ (+2%)21″ x 9.0-10.5″
265/35R2229.3″ (+2%)22″ x 9.0-10.5″
305/30R2229.2″ (+1.7%)22″ x 10.5-11.5″
315/25R2329.2″ (+1.7%)23″ x 11.0-12.0″
265/25R2429.2″ (+1.7%)24″ x n/a
145/80R2029.1″ (+1.4%)20″ x n/a
295/35R2129.1″ (+1.4%)21″ x 10.0-11.5″
255/45R2029″ (+1%)20″ x 8.0-9.5″
285/40R2029″ (+1%)20″ x 9.5-11.0″
325/35R2029″ (+1%)20″ x 11.0-13.0″
255/40R2129″ (+1%)21″ x 8.5-10.0″
255/35R2229″ (+1%)22″ x 8.5-10.0″
295/30R2229″ (+1%)22″ x 10.0-11.0″
305/25R2329″ (+1%)23″ x 10.5-11.5″
255/25R2429″ (+1%)24″ x n/a
285/35R2128.9″ (+0.7%)21″ x 9.5-11.0″
245/35R2228.8″ (+0.3%)22″ x 8.0-9.5″
245/25R2428.8″ (+0.3%)24″ x n/a
245/45R2028.7″ (Equal)20″ x 7.5-9.0″
275/40R2028.7″ (Equal)20″ x 9.0-11.0″
315/35R2028.7″ (Equal)20″ x 10.5-12.5″
325/30R2128.7″ (Equal)21″ x 11.0-12.0″
285/30R2228.7″ (Equal)22″ x 9.5-10.5″
275/35R2128.6″ (-0.3%)21″ x 9.0-11.0″
335/25R2228.6″ (-0.3%)22″ x 11.5-12.5″
275/30R2228.5″ (-0.7%)22″ x 9.0-10.0″
305/35R2028.4″ (-1.1%)20″ x 10.0-12.0″
315/30R2128.4″ (-1.1%)21″ x 10.5-11.5″
235/45R2028.3″ (-1.4%)20″ x 7.5-9.0″
265/40R2028.3″ (-1.4%)20″ x 9.0-10.5″
265/35R2128.3″ (-1.4%)21″ x 9.0-10.5″
265/30R2228.3″ (-1.4%)22″ x 9.0-10.0″
305/30R2128.2″ (-1.8%)21″ x 10.5-11.5″
315/25R2228.2″ (-1.8%)22″ x 11.0-12.0″
265/25R2328.2″ (-1.8%)23″ x 9.5-10.0″
295/35R2028.1″ (-2.1%)20″ x 10.0-11.5″
345/30R2028.1″ (-2.1%)20″ x 12.0-13.0″
225/45R2028″ (-2.5%)20″ x 8.0-9.5″
255/40R2028″ (-2.5%)20″ x 8.5-10.0″
255/35R2128″ (-2.5%)21″ x 8.5-10.0″
295/30R2128″ (-2.5%)21″ x 10.0-11.0″
355/25R2128″ (-2.5%)21″ x 12.5-13.5″
255/30R2228″ (-2.5%)22″ x 8.5-9.5″
305/25R2228″ (-2.5%)22″ x 10.5-11.5″
155/65R2027.9″ (-2.9%)20″ x n/a
285/35R2027.9″ (-2.9%)20″ x 9.5-11.0″
335/30R2027.9″ (-2.9%)20″ x 11.5-12.5″

*Disclaimer: Please note that our tire dimensions & measurements are an approximation number, while the tire manufacturers may have different ways in calculating or rounding numbers. We recommend referring to the vehicle manufacturer's manual or checking with the tire technician to find out the correct tire size for your vehicle.


Share on:

More tire sizes for 21" Wheel:

26″ Tire Diameter

27″ Tire Diameter

28″ Tire Diameter


29″ Tire Diameter

30″ Tire Diameter

31″ Tire Diameter

32″ Tire Diameter


Leave a Comment