Table of Contents

1. What is py-tire-height-calc?
2. Functions
   1. sidewall_height()
   2. wheel_height()
3. Example Use

What is py-tire-height-calc?

py-tire-size-calculator is a demonstration of calculating the height of a tire given its width, sidewall ratio, and rim size.

Given a tire size of 225/40R16, we can calculate the tire's height in inches as illustrated in the flowchart below:

flowchart LR;
    id1(225/40R16)-->|tire width|id2(225mm)-->|mm to in|id3(225mm / 25.4 = 8.85 in);
    id1-->|tire aspect ratio|id4(40)-->|divided by 100|id5(.40);
    id1-->|rim size|id7(16 inches);
    id3-->id96(8.85 x .40 = 3.54 in);
    id5-->id96;
    id96-->|x2|id97(7.08 in);
    id97-->|sidewall height|id98(7.08in + 16in);
    id7-->id98;
    id98-->id99(23.08 inches);

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Functions

sidewall_height()

Takes tread_width + sidewall as inputs and returns the sidewall height in inches.

Sidewall height must be divided by 100 in order to be used correctly as a percentage value.

Arguments

tread_width : int - tire width measured in millimeters

sidewall : int - the sidewall value listed on the tire size

def  sidewall_height(tread_width: int, sidewall: int) -> float:
	return (tread_width * (sidewall /  100)) /  25.4

wheel_height()

Takes tread_width, sidewall, and rim values as inputs. The tread width value is sent as an argument to sidewall_height() which returns a float of the sidewall height in inches.

Finally, wheel_height returns (sidewall height * 2) + rim size.

Arguments

tread_width : int - the tire width measured in millimeters

sidewall : int - the sidewall value listed on the tire size

rim : int - the height of the rim in inches

def  wheel_height(tread_width: int, sidewall: int, rim: int) -> float:
	return (sidewall_height_value *  2) + rim

Example Use

print(f"This wheel is: {wheel_height(225, 40, 16)} inches tall.")