# C Program to Calculate Simple Interest and Compound Interest

#### This C program calculates simple and compound interest given principal amount, rate and time by user.

Following formula are used in this program to calculate simple and compound interest in this C program:

Simple Interest = (P*T*R)/100

Compound Interest = P * ( (1+r/100 )t - 1)

## C Source Code: Simple & Compound Interest

``````
#include<stdio.h>
#include<conio.h>
#include<math.h>

int main()
{
float p, t, r, si, ci;
clrscr();
printf("Enter principal amount (p): ");
scanf("%f", &p);
printf("Enter time in year (t): ");
scanf("%f", &t);
printf("Enter rate in percent (r): ");
scanf("%f", &r);

/* Calculating simple interest */
si = (p * t * r)/100.0;

/* Calculating compound interest */
ci = p * (pow(1+r/100, t) - 1);

printf("Simple Interest = %0.3f\n", si);
printf("Compound Interest = %0.3f", ci);
getch();
return(0);
}
``````

## C Output: Simple & Compound Interest

```Enter principal amount (p): 5000 ↲
Enter time in year (t): 2 ↲
Enter rate in percent (r): 18 ↲
Simple Interest = 1800.000
Compound Interest = 1962.000

Note: ↲ indicates ENTER is pressed.
```