C program to calculate simple interest; In this tutorial, i am going to show you how to calculate simple interest in c program using function and normal formula.

## Algorithm and Programs to Calculate Simple Interest in C

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

### Algorithm to Calculate Simple Interest

Follow the below given algorithm to write a program to calculate simple 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 simple interest using formula
`SI = (principle * time * rate) / 100`

. - Finally, print the result of simple interest.

### C Program to Calculate Simple Interest using Formula

/** * C program to calculate simple interest */ #include <stdio.h> int main() { float principle, time, rate, SI; /* 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 simple interest */ SI = (principle * time * rate) / 100; /* Print the resultant value of SI */ printf("Simple Interest = %f", SI); return 0; }

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

Enter principle (amount): 10000 Enter time: 1.5 Enter rate: 5 Simple Interest = 750.000000

### C Program to Calculate Simple Interest using Function

/** * C program to calculate simple interest */ #include <stdio.h> // function for finding simple interest float SimpleInt(float p, float r, float t) { float si; si = (p * r * t)/100; // formula return si; // returning yhe value of si } int main() { float principle, time, rate, SI; /* 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 simple interest */ SI = SimpleInt(principle, rate, time); /* Print the resultant value of SI */ printf("Simple Interest = %f", SI); return 0; }

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

Enter principle (amount): 20000 Enter time: 2 Enter rate: 5 Simple Interest = 2000.000000