What size tire does my car need?

By Product Expert | Posted in How To, Mazda Service, Tips on Tuesday, June 11th, 2019 at 7:18 pm
A row of tires lined up on a white background. We can see through the hole of several of them, making it feel as by looking at this we're on the verge of dropping through the "portal" into some kind of tire-universe.

Finding Your Vehicle’s Tire Size

Buying new tires isn’t something we have to do all that often, so when the need does arise, it can be intimidating. One factor tire-buyers often encounter is size. Something they may have never thought about before is, “What size tires does my vehicle use?” “What tire size should a buy?” Ultimately, it comes down to, “What size tire does my car need?”


To find out what size tire your car needs, look to the tires currently fitted on your vehicle. On the side (referred to as the “sidewall”), there should be a long number that likely starts with a letter. This number contains all the necessary information about the size of your tire, and more- you just have to know how to read it.


A gloved hand is presses its palm solidly against the tire of a blue car.

How to Read Your Tire Number

There are three measurements in this number that relate to size: they tell you the tire width, aspect ratio, and wheel diameter.

  • The first three-digit number tells you the tire width. This is the measurement of the tire from sidewall to sidewall.
  • The two-digit number after the slash mark tells you the aspect ratio. Aspect ratio is the ratio of height to width of the tire. If the aspect ratio is 65, it means that the height of the tire’s cross-section is 65% of the tire’s width.
  • The next two-digit number tells the wheel diameter. This lets you know the size of wheel that the tire is designed to fit. The diameter refers to the measure of the wheel from one end to the other.

With the help of these three numbers, you should be able to tell what tire size is used by your vehicle. If you have any further questions, feel free to contact us here at Hall Mazda near Milwaukee!

Note: the parts of this number that don’t relate to size are used to indicate tire type and performance.

Read More: Approximately How Long Does a Set of Tires Last?

Where to Buy New Tires near Milwaukee, WI

If you’re in need of new tires in the Milwaukee area, check out our Tire Center here at Hall Mazda! We provide competitive prices, expert installation, all the major brands you know and love, and road hazard coverage for eligible tires. We’ll make sure you get the right tires (including size) for your vehicle.

Thanks for reading, and we hope to see you soon!

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One Response to “What size tire does my car need?”

  1. Ellie Wilson says:

    Everyone should be aware of the basic aspects of car maintenance tricks required to keep the vehicle in working order. As far as tire replacement is concerned it should be left to the experienced professionals. The tread depth of the tire should be measured after certain time interval and tires with lesser tread depth should be replaced with suitable substitutes in order to get better control over the vehicle and to reduce the possibility of any kinds of accident. For more information, visit https://www.professionalautomotive.com/tire

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