C Programming

Math Constant Pi Value in C

The ratio of the circumference to the diameter of a circle is known as the mathematical constant Pi (π). This ratio, which is around 3.141593, is irrational. It is often used in geometry, trigonometry, and mathematical analysis in a variety of calculations and formulas. Pi is an important constant that has been known since ancient times, but its exact value was discovered in the 18th century. This value is used in a variety of mathematical applications and is widely recognized as the number used to calculate the circumference of a circle.

If you are implementing a C code and need the Pi value at some point, you will need guidance on how to use Pi constant value in programming. If you’re looking for assistance on the concept of Pi, read this article.

Pi Constant Value in C Language

The C programming language is a versatile language used in many software applications. It is commonly used for writing code for embedded systems, desktop applications, web applications, and various other software programs. The C language also allows for the use of constants, which are fixed values that can be used in code. In particular, the constant value of Pi in the C language is a very important constant that can be used in many mathematical calculations.

When using Pi in C programming, it is not necessary to write out the full decimal value of the constant. Instead, it is more common to use a shorter version known as the hexadecimal form. This form is represented as 0x3F, which in hexadecimal is the same value as 3.14159. This allows for easier typing, instead of having to type out all the decimal digits. It should also be noted that this hexadecimal form is not exact, so it is best used when the accuracy of calculations is not critical.

The M_PI constant, which is specified in the <math.h> header file can be used to represent Pi in C programs. An example of the Pi constant is given below.

#include <stdio.h>

#include <math.h>

int main() {

  double rad = 7.4;

  double area_Of_Circle = M_PI * rad * rad;

printf("The area of a circle with radius %lf is %lf\n", rad, area_Of_Circle);

printf("The Value of Pi here is %lf is %lf\n", M_PI);

  return 0;


In this code, we use the formula A = πr^2 to get the area of a circle of radius 7.4, where r is denoted by M_PI.


Final Thoughts

Pi is an important mathematical constant widely used in a variety of calculations and formulas. It is represented in the C programming language as 0x3F, and its value is 3.141593. The above-mentioned guidelines present a code as well to help users how to use the Pi value in a mathematical calculation or separately find its value in the C program. The users can use the “M_PI” with double data type in a program to use the Pi value in the calculation.

About the author

Hiba Shafqat

I am a Computer Science student and a committed technical writer by choice. It is a great pleasure to share my knowledge with the world in which I have academic expertise.