What Does 215/45r17 Tire Size Mean? – Explained

Are tire sizes giving you problems? Do you know how to determine the class of each tire? There is no need to worry anymore. In this article, we shall look at all the aspects concerning this 215/45r17 tire, its size, quality, and all the ratings.

Tires do not bear similar characteristics, especially when it comes to size and construction. Most of the users are not able to differentiate between these products, but we are going to simplify everything by talking more about 215/45r17 tire size.

We intend to help make the best decision when purchasing new tires for your car. Read through the article for more information.

What does 215/45r17 tire size mean?

These numbers and letters have different meanings. They are as follows:

215 – means the section width of the tire in millimeters. The section width, also known as cross-section width is the measurement of linear width from one sidewall to the other. However, it does not include any raised letters, protective ribs, and any other form of ornament.

45 – is the aspect ratio of the tire. It is always measured in percentage, meaning that the ratio of this tire is 45%. A tire with more ratio means that it has a bigger and taller sidewall.

R – stands for the construction type of the tire. R means that it is a radial type. There are two types of construction, and these are radial and cross-ply.

In our case, the construction type is radial.

17 – is the wheel diameter of the tire. The diameter is the measurement from the end of the tire to the other through the center.

It also means the tire is designed to fit the wheels or rims that have a diameter of 17 inches.

The table of 215/45r17 tire size with Parameter

21545r17 Tire Size
Section width8.5 inches
Sidewall height3.8 inches
Revolutions per mile820
Tire diameter24.6 inches
Circumference77.3 inches
Rim width range17 inches x 7-8 inches

The section width

The measurement of the tire from the inner sidewall to the outer one is the section width. It is not similar for all the tires. Some are bigger than others.

The section width of the 215/45r17 tire is 8.5 inches. In other units, it is expressed as 215.9 millimeters, but they mean the same thing.

The sidewall height

It means the length or the height of the sidewall from the wheel rim to the top of the tread. It is expressed as a percentage concerning the tire width.

In our case, the aspect ratio is 45. It means the sidewall height is 45% as high as the width of the tire.

To obtain the sidewall height, convert the tire width, in this case, 215mm, to inches (3.5 in).

The revolutions per mile

The revolutions per mile, or the RPM, is the number of complete rotations a tire makes within a mile. Each type of tire has its standard measurement of RPMs.

A 215/45r17 makes 820 revolutions per every single mile.

The tire diameter

Diameter refers to the total length of the tire from one side to the other through the center. It divides the tire and the rim into two equal parts.

The tire diameter of 215/45r17 is 24.6 inches. It is wide enough to fit a 17-inch tire.

The circumference

If you measure the distance of the tire through the outer edge on the highest point of the sidewall, from one point to the same on a tire, you will get the circumference. It is the distance around the tire.

It is the longest distance on the tire, unlike the diameter that cuts straight through the center.

The circumference of the 215/45r17 tire is 77.3 inches.

The rim width range

It means the range of tire sizes that a rim would fit. Generally, tires of different sizes can fit into a single rim on condition that their differences are not more than 3%.

The acceptable limit for changing the tire from one size to another should be strictly 3%. If you exceed the limit, the tire won’t fit. It would be loose. Alternatively, if you select the small one, it would not expand to fit a large rim.

The rim width range of 215/45r17 is 17 inches x 7-8 inches, meaning that a tire with a rim width of 7 to 8 inches can fit in comfortably.

Also Read: 215 45r17 vs 215 50r17 Tire Size – Checked Comparison

Frequently asked questions

What is 215 tire size?

For a person who does not understand the above terms, 215 means the tire’s width. The distance from the end of the sidewall to the other is 215mm.

There are many tires of this size, and differentiating it can be a challenge. You can use other aspects to determine the accurate size of the tire. They include things like the aspect ratio, the construction, and the rim width.

What rim size fits 215/45r17?

In essence, the number 17 on the tire means that it fits the rim size seventeen. However, a tire can fit several sizes without many problems.

It is not possible to put wide tires to narrow reams, and the opposite is true.
For this type of tire, you need a 17-inch x 7-8-inch rim or rims.

How wide is this tire?

It is not possible to deduce the width of the tire from its name. However, the tires that fall into this class have a section width of 8.5 inches.

That means it measures 8.5 inches from one side of the tire to the other when standing on the ground.

How much is difference is allowed when replacing a tire?

When changing from one tire size to another, it is advisable to follow the pre-set guidelines. The acceptable difference when changing from one tire size to another should not exceed 3%.

Having a tire more than that allowable percentage will be dangerous to both the car and the user.


215/45r17 is one of the most common tires on our roads. However, many people do not know most about it. The article presents most of the information about this product in a well-researched project.

As the name says, the tire has a width of 215mm, an aspect ratio of 45%, is of radial construction, and fits a rim width of 17 inches.

Best of luck as you buy one for your car.

I am an engineer and the chief editor of tireslover.com, I am a passionate blogger as well. I am the person who can ensure a perfect, informative, honest, and helpful, guide with 10 years of work experience with different varieties of tires.

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