Reading a tire can be very confusing! There are so many numbers and letters on your tire’s sidewall, and they have no description on them. Often, if you call a towing company, they will ask for numbers and letters off your tire’s sidewall before they can come help you. The right combination of this information will equal your tire size.
Use this easy-to-read diagram to learn more about your tires!
Diagram Key:
| Tire Diagram Letter | What Does it Mean? |
| A | Tread Wear Indicators |
| B | Tubeless |
| C | Tire Ply Composition and Materials |
| D | Tire Type (Special Trailer) |
| E | Width of Tire in Millimeters |
| F | Aspect Ratio (Ratio of Height to Width) |
| G | Construction Type (R=Radial, D=Bias) |
| H | Wheel Diameter in Inches |
| I | Load Index |
| J | Speed Rating |
| K | Tire Construction (Radial or Bias) |
| L | U.S. DOT Safety Standard Code |
| M | Maximum Cold Inflation and Load Limit |
| N |
Load Range
|
| O | Safety Warning |
How to read tire size:
The most important information you'll likely need from your tire is the size. Dealerships or whoever you are buying tires from will need to know the exact size to get you the correct tires for your vehicle. This tire size chart breaks down exactly how to read tire size.
Letters D-K explained, from the diagram above.
| From the Tire | What Does it Mean? |
| ST | Tire Type (Special Trailer) |
| 235 | Width of Tires in Millimeters |
| 80 | Aspect Ratio (Ratio of Height to Width) |
| R or Radial | Construction Type |
| 16 | Wheel Diameter in Inches |
| 119/114 | Load Index |
| M | Speed Rating |
Speed Rating Breakdown:
| A | Up to 25 MPH |
| B | Up to 31 MPH |
| C | Up to 37 MPH |
| D | Up to 40 MPH |
| E | Up to 43 MPH |
| F | Up to 50 MPH |
| G | Up to 56 MPH |
| J | Up to 62 MPH |
| K | Up to 68 MPH |
| L | Up to 75 MPH |
| M | Up to 81 MPH |
| N | Up to 87 MPH |
| P | Up to 93 MPH |
| Q | Up to 100 MPH |
| R | Up to 106 MPH |
| S | Up to 112 MPH |
| T | Up to 118 MPH |
| U | Up to 124 MPH |
| H | Up to 130 MPH |
| V | Up to 149 MPH |
| W | Up to 168 MPH |
| Y | Up to 186 MPH |
| Z | 149 MPH and over |
Now you're all ready to read your tires! Happy driving!
