C program Simple Interest and Compound Interest

This is a C programming code which calculates banking interest on principle amount for N years using Simple interest formula and Compound Interest formula. The input values for principle amount and number of years is read from user.

Simple interest - formula

• I - Interest Amount
• P - Principle Amount to be deposited
• N - Number of years the principle amount to be deposited
• R - Rate of interest per year in percentage

Simple interest - example calculation

 
           Assume that, we are going to deposit 5000$ in bank
                at rate of interest 8% for 5 years, 

           calculate simple interest for the principle amount after 5 years
         
            P=5000;  R =8;  N=5;  I =?

             I = 5000 x 5 x 8/100
             I = 25000  x 0.08 
             I = 2000$          

         after 5 years , we will get additionally 2000$ as interest 
                          along with principle amount (10000$).                   
    

Simple Interest - C programming code

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

int main() {

   float A,R,N;   
   float si=0;
   
   printf ("Find a simple interest for principle amount");
   
   printf("\n Enter principle amount :" );
   scanf("%f", &A);
   printf("\n Enter interest in percentage  :" );
   scanf("%f", &R);
   printf("\n Enter number of year :" );
   scanf("%f", &N);
   
   si =  A * (R/100) * N;
   
   printf("Simple Interest  is : %.2f",si);
   printf(" Total Amount  after %.1f is : %.2f",(A+si)); 
   
 return 0;
}
 

Simple Interest - C programming output

 Find a simple interest for principle amount
 Enter principle amount :5000

 Enter interest in percentage  :8

 Enter number of year :5
Simple Interest after 5.0 is : 2000.00

Compound interest - formula

• I - Interest Amount
• P - Principle Amount to be deposited in bank
• N - Number of years the principle amount to be deposited
• R - Rate of interest per year in percentage

Compound interest - example calculation

In compound interest - The principle amount is increased every year due to accumulating interest of principle amount with principle amount. so that,finally compound interest gives greater value than simple interest.

 
           Assume that, we are going to deposit 5000$ in bank
                at rate of interest 8% for 5 years, 

           calculate compound interest for the principle amount after 5 years
         
            P=5000;  R =8;  N=5;  I =?

             I = 5000 x (1 + 8/100)5  - 5000
             I = 5000 x (1 + 0.08)5  - 5000
             I = 5000 x (1.08)5  - 5000       
             I = 5000 x 1.46932  - 5000
             I = 7346 - 5000 
             I = 2346$

         after 5 years , we will get additionally 2346$ as interest 
                          along with principle amount (10000$).                   
    

Compound Interest - C programming code

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

int main() {

   float A;
   float R;
   float N;
   float ca=0;
   
   printf ("Find a compound interest for principle amount");
   printf("\n Enter principle amount :" );
   scanf("%f", &A);
   printf("\n Enter interest in percentage  :" );
   scanf("%f", &R);
   printf("\n Enter number of year :" );
   scanf("%f", &N);

   ca = A * pow( (1+R/100),N);  
 
  printf(" Compound Interest after %.1f is : %.2f",(ca-A));  
  printf(" Total Amount plus principle amount after %.1f is : %.2f",ca); 
   
 return 0; 
}

Compound Interest - C program Output

 Find a compound interest for principle amount

 Enter principle amount :5000
 Enter interest in percentage  :8
 Enter number of year :5

 Compound Interest after 5.0 is : 2346.64
 Total Amount plus principle amount  after 5.0  : 7346.64