Write a C program to input principle (amount), time and rate (P, T, R) and find Compound Interest. How to calculate compound interest in C programming. Logic to calculate compound interest in C program.
Example
Input
Input
Enter principle (amount): 1200 Enter time: 2 Enter rate: 5.4
Output
Compound Interest = 1333.099243
Required knowledge
Arithmetic operators, Operator precedence and associativity, Data types, Basic input/output
Compound Interest formula
Formula to calculate compound interest annually is given by.

Where,
P is principle amount
R is the rate and
T is the time span
Logic to calculate compound interest
Step by step descriptive logic to find compound interest.
- Input principle amount. Store it in some variable say principle.
- Input time in some variable say time.
- Input rate in some variable say rate.
- Calculate compound interest using formula,
CI = principle * pow((1 + rate / 100), time). - Finally, print the resultant value of CI.
Read more – Program to find power of a number
Program to calculate compound interest
/** * C program to calculate Compound Interest */ #include <stdio.h> #include <math.h> int main() { float principle, rate, time, CI; /* Input principle, time and rate */ 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 CI */ printf("Compound Interest = %f", CI); return 0; }Output
Enter principle (amount): 1200 Enter time: 2 Enter rate: 5.4 Compound Interest = 1333.099243
Happy coding 😉