Here we are explaining how to write a java program to find the compound interest. So first we have to read the principal amount, interest per year, and time period, number of times the interest is compounded from the user. Then we can calculate the compound interest.

We can calculate the compound interest by using the formula,

**Compound Interest=P (1 + R/n) ^{(nt)} - P**

where P is the Principal amount.

R is the Interest rate per Annum.

t is the time period n is the number of times the interest is compounded per t.

For reading a double value from the user in java, we can use nextDouble() function in the java Scanner class. In this program, we have to read the principal amount, interest rate, time as double. So we have to write the code as follows:

`System.out.print("Enter the Principal amount : ");`

`p = sc.nextDouble();`

First, we have to declare the class CInterest.Then open the main function. Then declare the variables p,r,t, ci as double and n as an integer. Read the principal amount from the user into the variable p.Read the rate of interest per annum in the variable r. Read the time period from the user into the variable t. Read the number of times the interest is compounded into the variable n.Then calculate compound interest as ci= p * Math.pow(1 + (r / n), n * t).Then display compound interest as ci using `system.out.println()`

function.

**STEP 1**: Declare the class CInterest with a **public **modifier.

**STEP 2**: Open the **main()** to start the program, Java program execution starts with the **main()**

**STEP 3**: Declare the variables **p**,**r**,**t**, **ci** as double and **n** as an integer.

**STEP 4**: Read the principal amount from the user into the variable **p**.

**STEP 5**: Read the rate of interest into the variable **r**.

**STEP 6**: Read the time period in the variable **t**.

**STEP 7**: Read the number of times the interest is compounded into the variable n.

**STEP 8**: calculate compound interest as **p * Math.pow(1 + (r / n), n * t)**.

**STEP 9**: Display the compound interest.

` ````
import java.util.Scanner;
public class CInterest
{
public static void main(String args[])
{
double p,r,t,ci;
int n;
Scanner sc = new Scanner(System.in);
System.out.print("Enter the Principal amount : ");
p = sc.nextDouble();//Read Principal amount
System.out.print("Enter the Rate of interest : ");
r = sc.nextDouble();//Read rate of interset
System.out.print("Enter the number of times the interest is compounded : ");
n = sc.nextInt();//Read n
System.out.print("Enter the Time period : ");
t = sc.nextDouble();//Read the time period
sc.close();
ci = p * Math.pow(1 + (r / n), n * t);
System.out.print("Compound Interest is: " +ci);
}
}
```

OUTPUT 1 Enter the Principal amount :2000 Enter the Rate of interest per year : 0.08 Enter the number of times the interest is compounded :12 Enter the time period in year : 5 Compound Interest is:2979.69141660321