Car Tire Numbers Explained – What Do The Numbers Mean?




Car tire numbers are explained using the letters and numbers printed on the side of the tire. These numbers tell you the tires purpose, the complete dimensions, the total load/weight capacity, speed rating and more. These specifications are referred to as the tire code. The specs on the sidewall of your tires will always include the tire size, radial construction, the type of vehicle the tire was made for, speed rating, and PSI inflation rating.  The PSI inflation rating specifies the maximum PSI that the tire can safely hold. Tire specs also include something called load rating. This is important for hauling or towing a trailer. Read below for a complete tire guide.

tire-size-explainedWidth – Aspect Ratio – Radial – Diameter – Maximum Load – Maximum Speed



Car tire numbers explained – Tires will have something similar like this printed on the side of it: P215/65R17 95H

The first letter means type of tire for certain vehicles.
P = Passenger vehicles tire
T = Truck vehicles tire

The 3 digit number (215) is the Width. This number refers to the tire width in millimeters. It is measured in millimeters from sidewall to sidewall.

The 2 digit number (65) is the Aspect Ratio. It is the ratio of the height of the tire’s cross-section to its width. The number 65 means the height is equal to 65% of the width of the tire.



The letter (R) stands for Radial. This means the layers run radially across the tire.

The number (17) is Wheel Diameter. It is the size of the wheel measured from one end to the other. It tells you the size of the wheel that the tire is intended to fit on.

The next number (95) is the Load Index. Load Index shows the maximum load that the tire can support when inflated properly. You can also find the maximum load on the tire sidewall in both LBS pounds and KG kilograms.

worn-out-tire-chart-help-identificationIdentify what may be causing your tires to wear out by using this chart

The last letter (H) identifies the Speed Rating. The speed rating tells you the maximum speed capability of a tire. A tire with an H speed rating has a maximum speed capability of 130 mph.

Here is a chart that will identify your tire speed rating. The last letter on your tire will be one of the letters below:
M = 81 mph
N = 87 mph = Spare Tires
P = 93 mph
Q = 99 mph = Winter Tires
R = 106 mph = Truck Tires
S = 112 mph = Cars and Minivans
T = 118 mph = Cars and Minivans
U = 124 mph = Sport Performance Cars
V = 149 mph = High Performance Cars
W = 168 mph = Ultra High-Performance Cars
Y = 186 mph = Ultra High-Performance Cars

tirespeedsymbolchart



 

If you are curious, the most common tire size is the R15. The most common tires used with the R15 size are the P235/75R15, P205/65R15, and the P215/70R15. An R15 tire is fitted with a 15-inch rim. The P tire variant is the most common R15 tire. This tire is made and designed for normal average passenger vehicles. The R16 is a bigger version of the R15 tire. The most popular variant of this tire is the P225/60R16 and designed for most passenger vehicles.



How To Read Tire Sizes and Specifications

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18 thoughts on “Car Tire Numbers Explained – What Do The Numbers Mean?”

  1. Hi everyone,
    I got 2013 Cadillac XTS currently I have P245/40R20 95V can I replace it with P245/40R20 99W? As you see the difference between two is 95V vs 99W.

  2. Is there a problem to use a 215/60r17 tire on a car that uses 215/55r17 tires?
    So the aspect ratio is 5 more on the tire I want to use on the car?

  3. I have a 09 Gallant it has 215/60r16 95H tires can I replace them with 225/60r16 98H? It seems like the only difference will be the new ones will be just a small amount wider.

  4. I have winter tires 215/55R17. Can I use these on a Murano 2016 with tires 235/65R18? I will buy 17 inch wheels to fit the 17 tires, but will they be OK on the Murano?

    1. DIY Project Help Tips

      Simon Nguyen,
      We don’t see a problem if the 17″ wheels are the proper size for the tires and the car is not too low where the tires rub on the fenders.
      Call a tire sales company near you and ask them to be absolutely sure.
      -RR

  5. I have a Kia Rio 2001 with size 185/65R14 tires and want to change to tire size 186/65R15. There seems to be 4.3 percent difference in everything except the width, which is the same for both tires. Will this work?

    1. DIY Project Help Tips

      Vicky Braden,
      Should be just fine.
      Just be sure the tires do not hit the fenders because the height is too high.
      The width should be okay.
      Find out the distance or clearance from the wheel hub to the top of the inner wheel well.
      -RR

      1. -RR,
        Do you think the last two digits in her options make a difference? Or should they be just fine? I’m pretty sure – no, positive, that a 15″ tire will not fit a 14″ wheel……

        1. DIY Project Help Tips

          Wolfy,
          This was “assuming” the wheel was the correct size for the 15″ tire.
          And no it is not possible for a 15″ tire to fit on a 14″ wheel… agreed.
          -RR

  6. Great diagram for identifying the numbers on tires.
    I have always wondered exactly what those things mean.
    I knew they were important, but I never investigated.
    I at least check my tire pressure frequently, that’s good.
    Do you think I should replace my tires soon?

  7. Good information,
    The fact is the the tire height is actually comprised or determined from/by in the example above using
    the “WIDTH” and “Aspect Ratio”. Here is a list of 16″ tire heights.
    W/AR/D/ Height
    205 40 16 22.46
    215 40 16 22.77
    225 40 16 23.09

    195 45 46 22.91
    205 45 16 23.26
    215 45 16 23.62
    225 45 16 23.97
    245 45 16 24.68

    195 50 16 23.68
    205 50 16 24.07
    215 50 16 24.46
    225 50 16 24.86
    235 50 16 25.25
    245 50 16 25.65
    255 50 16 26.04
    265 50 16 26.43
    275 50 16 26.83
    295 50 16 27.61

    195 55 16 24.44
    205 55 16 24.88
    215 55 16 25.31
    225 55 16 25.74
    235 55 16 26.18
    315 55 16 29.64
    345 55 16 30.94

    205 60 16 25.69
    215 60 16 26.16
    225 60 16 26.63
    235 60 16 27.10
    285 60 16 29.46

    205 65 16 26.49
    215 65 16 27.00
    255 65 16 29.05
    275 65 16 30.07

    205 40 16 22.46
    215 40 16 22.77
    225 40 16 23.09

    195 45 16 22.91
    205 45 16 23.26
    215 45 16 23.62
    225 45 16 23.97
    245 45 16 24.68

    195 50 16 23.68
    205 50 16 24.07
    215 50 16 24.46
    225 50 16 24.86
    235 50 16 25.25
    245 50 16 25.65
    255 50 16 26.04
    265 50 16 26.43
    275 50 16 26.83
    295 50 16 27.61

    195 55 16 24.44
    205 55 16 24.88
    215 55 16 25.31
    225 55 16 25.74
    235 55 16 26.18
    315 55 16 29.64
    345 55 16 30.94

    205 60 16 25.69
    215 60 16 26.16
    225 60 16 26.63
    235 60 16 27.10
    285 60 16 29.46

    205 65 16 26.49
    215 65 16 27.00
    255 65 16 29.05
    275 65 16 30.07

    255 75 16 31.06

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