# Basic C Exercises

**C program to calculate Compound Interest**

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.

**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