C program to calculate compound interest; Through this tutorial, you will learn how to calculate compound interest in the c program with the help of function, and normal formula.

## Programs to Calculate Compound Interest in C

- Algorithm to Calculate Compound Interest
- C Program to Calculate Compound Interest using Formula
- C Program to Calculate Compound Interest using Function

### Algorithm to Calculate Compound Interest

Use the following algorithm to write a program to calculate compound interest; as follows:

- Get input principle amount and store in some variable.
- Get input time and store in some variable..
- Get input rate and store in some variable..
- To calculate compound interest using formula
`CI = principal*((1+rate/100)time-1)`

. - Finally, print the result of compound interest.

### C Program to Calculate Compound Interest using Formula

/* C program to enter P, T, R, and calculate Compound Interest */ #include <stdio.h> #include <math.h> int main() { float principle, time, rate, CI; /* Input principle, rate and time */ printf("Enter principle (amount): "); scanf("%f", &principle); printf("Enter time: "); scanf("%f", &time); printf("Enter rate: "); scanf("%f", &rate); /* Calculate compound interest */ CI = principle * (pow((1 + rate / 100), time)); /* Print the resultant value of CI */ printf("Compound Interest = %f", CI); return 0; }

**The output of the above c program; as follows:**

Enter principle (amount): 5000 Enter time: 7 Enter rate: 9 Compound Interest = 9140.197266

### C Program to Calculate Compound Interest using Function

/* C program to enter P, T, R, and calculate Compound Interest using function */ #include <stdio.h> #include <math.h> // function for finding compound interest float CmInt(float p, float r, float t) { float ci; ci = p * (pow((1 + r / 100), t)); return ci; // returning yhe value of ci } int main() { float principle, time, rate, CI; /* Input principle, rate and time */ printf("Enter principle (amount): "); scanf("%f", &principle); printf("Enter time: "); scanf("%f", &time); printf("Enter rate: "); scanf("%f", &rate); /* Call function with paramters to Calculate compound interest */ CI = CmInt(principle, rate, time); /* Print the resultant value of CI */ printf("Compound Interest = %f", CI); return 0; }

**The output of the above c program; as follows:**

Enter principle (amount): 1000 Enter time: 5 Enter rate: 5 Compound Interest = 1276.281250