P315/45R17 Tire Size in Inches & Millimeters

Tire size “315/45R17” indicates your vehicle’s specifications based on tire width, aspect ratio, height, tire construction, diameter, radial and inches. These tire size numbers represent our tire sizes in both Metric (in millimeters) and Imperial (in inches) units of measurement to help find the correct tire size for your vehicle.

To convert tire size P315/45R17 to inches, you must know what these numbers represent.

So let us know P315/45R17 in simple words:

First number “315” indicates the tire’s width in millimeters.
Second number “45” refers to the aspect ratio, which is the height of the tire’s sidewall as a percentage of its width.
Third number “R17” refers to a tire that is designed to fit a 17-inch diameter rim.

Therefore, when converting the tire size P315/45R17 to inches, it can be concluded that the width of the tire will be approximately 12.4 inches ( 315 mm= 12.4 in), and the sidewall height will be approximately 5.6 inches (45% of 12.4 inches = 5.6 inches).

How to convert P315/45R17 into Inches (imperial)?

To convert tire size P315/45R17 to inches (Imperial) –

1. Width conversion: To convert it to inches, you can use a conversion factor of approximately 25.4 millimeters per inch.

  • 315 millimeters/25.4 = approximately 12.4 inches
    So, the width of the tire is approximately 12.4 inches.

2. Aspect Ratio Calculation: To calculate sidewall height in inches, you can use the tire width (from Step 1) and the aspect ratio:

  • Sidewall Height = Width (in inches) * Aspect Ratio / 100
  • Sidewall Height = 12.4 inches * 45/100 = approximately 5.6 inches
    So, the tire sidewall height is approximately 5.6 inches.

3. Rim Diameter: The “R” in the tire size stands for “radial construction” and the last number “17” indicates the rim diameter in inches. In this case, it’s already in inches.
So, the converted tire size “P315/45R17” in inches (imperial) is approximately:

  • Width: 12.4 inches
  • Sidewall Height: 5.6 inches
  • Rim Diameter: 17 inches

How to convert P315/45R17 into Millimeters (metric)?

To convert the tire size P315/45R17 into millimeters (metric) –

1. Width Conversion: The first number in the tire size, “315“, represents the tire’s width in millimeters. Since it’s already in millimeters, there’s no need for conversion.

  • Width: 315millimeters

2. Aspect Ratio Calculation: The second number “45” is the aspect ratio, representing the tire’s sidewall height as a percentage of its width. To calculate the sidewall height in millimeters, you can use the tire’s width (from step 1) and the aspect ratio:

  • Sidewall height = Width (in millimeters) * Aspect Ratio / 100
  • Sidewall height = 315 millimeters * 45 / 100 = 142 mm millimeters
    So, the tire’s sidewall height is approximately 142 mm millimeters.

3. Rim Diameter: The “R” in the tire size stands for “radial construction” and the last number, “17” indicates the rim diameter in inches. To convert this to millimeters, you can use the conversion factor of approximately 25.4 millimeters per inch.

  • Rim diameter = 17 inches * 25.4 millimeters per inch = 432 mm millimeters
    So, the rim diameter is approximately 432 mm millimeters.

So, the converted tire size “P315/45R17” in millimeters (metric) is approximately:

  • Width: 315 mm
  • Sidewall Height: 142 mm
  • Rim Diameter: 432 mm

Alternate Tire Size of P315/45R17 For replacement

Tire Size Overall Diameter Difference
235/45R19 27.4″ (695 mm) -2.9%
265/45R18 27.4″ (695 mm) -2.9%
265/40R19 27.4″ (695 mm) -2.9%
165/80R17 27.4″ (696 mm) -2.8%
305/35R19 27.4″ (697 mm) -2.7%
355/30R19 27.4″ (697 mm) -2.7%
295/45R17 27.5″ (698 mm) -2.5%
205/65R17 27.5″ (698 mm) -2.5%
345/35R18 27.5″ (699 mm) -2.4%
155/70R19 27.6″ (701 mm) -2.1%
305/40R18 27.6″ (701 mm) -2.1%
225/60R17 27.6″ (702 mm) -2%
245/55R17 27.6″ (702 mm) -2%
245/50R18 27.7″ (703 mm) -1.8%
205/60R18 27.7″ (703 mm) -1.8%
315/35R19 27.7″ (703 mm) -1.8%
275/40R19 27.7″ (703 mm) -1.8%
145/85R18 27.7″ (703 mm) -1.8%
245/45R19 27.7″ (703 mm) -1.8%
225/55R18 27.8″ (705 mm) -1.5%
275/45R18 27.8″ (705 mm) -1.5%
155/80R18 27.8″ (705 mm) -1.5%
305/45R17 27.8″ (706 mm) -1.4%
275/50R17 27.9″ (708 mm) -1.1%
345/40R17 27.9″ (708 mm) -1.1%
315/40R18 27.9″ (709 mm) -1%
285/40R19 28″ (711 mm) -0.7%
255/55R17 28″ (712 mm) -0.6%
215/65R17 28″ (712 mm) -0.6%
155/90R17 28″ (712 mm) -0.6%
255/50R18 28.1″ (713 mm) -0.4%
285/45R18 28.1″ (713 mm) -0.4%
255/45R19 28.1″ (713 mm) -0.4%
235/60R17 28.1″ (714 mm) -0.3%
235/55R18 28.1″ (715 mm) -0.1%
145/80R19 28.1″ (715 mm) -0.1%
235/50R19 28.3″ (719 mm) 0.4%
295/40R19 28.3″ (719 mm) 0.4%
155/85R18 28.4″ (721 mm) 0.7%
265/45R19 28.4″ (721 mm) 0.7%
265/50R18 28.5″ (723 mm) 1%
295/45R18 28.5″ (723 mm) 1%
265/55R17 28.5″ (724 mm) 1.1%
225/65R17 28.5″ (724 mm) 1.1%
345/35R19 28.5″ (725 mm) 1.3%
245/60R17 28.6″ (726 mm) 1.4%
245/55R18 28.6″ (727 mm) 1.5%
225/60R18 28.6″ (727 mm) 1.5%
245/50R19 28.7″ (729 mm) 1.8%
165/90R17 28.7″ (730 mm) 2%
155/80R19 28.8″ (731 mm) 2.1%
275/45R19 28.8″ (731 mm) 2.1%
225/55R19 28.8″ (731 mm) 2.1%
305/45R18 28.8″ (731 mm) 2.1%
275/50R18 28.9″ (733 mm) 2.4%
215/70R17 28.9″ (734 mm) 2.5%
275/55R17 28.9″ (734 mm) 2.5%
315/40R19 28.9″ (735 mm) 2.7%
155/90R18 29″ (737 mm) 2.9%
175/80R18 29″ (737 mm) 2.9%
255/55R18 29″ (737 mm) 2.9%

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