Tire size comparison the easy way before you buy. Use our tire size calculator to compare diameter, width, sidewall, circumference and revolutions per mile for 2 tires.

Tire size calculator takes two tire sizes and directly calculates the differences between the tires diameter, width, sidewall, circumference and revolutions per mile.
Metric or imperial output available.
It also shows examples of your speedometer reading with the first tire, and the actual speed you're traveling if you were to install the second tire.
A illustration between 2 tire size and shape are show for better understanding on how it look like.
A very useful tool when searching for tires that are a different size then stock. Enjoy this app for all your tire size comparison needs.

Check Your Tire's Sidewall:
- With a little explanation it's easy to understand what all of the letters and numbers mean on your tire's sidewall. The numbers are indicators of the size, type, and performance of the tire.
- Tire Type The letter "P" at the beginning of the "Tire Size" tells us the tire is a P-Metric tire, referring to tires made to certain standards within the United States, intended for Passenger vehicles.
- If a tire size has no letters at the beginning, this indicates a Euro metric tire. P-Metric and Euro-Metric tires may have different load capacities.
- The letters "LT," either at the beginning or at the end of the tire size indicate the tire was designed for light trucks. Vehicle manufacturers equip some light trucks with "LT" type tires. These tires generally require higher inflation pressures than passenger tires.
- Consult your owner's manual or tire placard for the recommended tire size and inflation pressure for your vehicle.

Tire Width is the width of the tire measured in millimeters from sidewall to sidewall. The first three-digit number in the tire size refers to the tire width. For instance, in a size P220/40 R17 tire, the width is 220 millimeters.

Aspect Ratio is the ratio of the height of the tire's cross-section to its width. The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size P220/40 R17 tire, the 40 means that the height is equal to 40% of the tire's width. The bigger the aspect ratio, the bigger the tire's sidewall will be.

Construction. The letter "R" in a tire size stands for Radial, which means the layers run radially across the tire.

Wheel Diameter is the size of the wheel measured from one end to the other. It tells us the size of the wheel that the tire is intended to fit. A size P220/40 R17 tire is made for a wheel with a 17 in diameter.

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What’s New

Version 1.2

- Update for Newest Devices
- Minor Bug Fixed

Ratings and Reviews

4.7 out of 5
3 Ratings

3 Ratings

best ACCM ,

I want my money back, absolutely useless

This is the worst ap I have ever used. Hard to navigate, doesn’t provide the information anyone needs to compare sizes. I want my money back

BigA409 ,

Doesn't work

This app doesn't work. When you input a tire size, the app changes it to some default number. This keeps happening. Don't buy.

Cadiddlehopper56 ,

Parts sales

Total rip-off doesn’t work.

App Privacy

The developer, Nitrio, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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