# Calculate compound interest in JavaScript

## Compound Interest Formula

Compound interest is calculated using the following formula −

CI = P*(1 + R/n) (nt) – P

Here,

• P is the principal amount.
• R is the annual interest rate.
• t is the time the money is invested or borrowed for.
• n is the number of times that interest is compounded per unit t, for example if interest is compounded monthly and t is in years then the value of n would be 12. If interest is compounded quarterly and t is in years then the value of n would be 4.

We are required to write a JavaScript function that takes in principal, rate, time, and the number n and calculates the compound interest.

## Example

Let’s write the code for this function −

const principal = 2000;
const time = 5;
const rate = .08;
const n = 12;
const compoundInterest = (p, t, r, n) => {
const amount = p * (Math.pow((1 + (r / n)), (n * t)));
const interest = amount - p;
return interest;
};
console.log(compoundInterest(principal, time, rate, n));

## Output

The output in the console: −

979.6914166032097