Compound Interest Calculator

How to use the Compound Interest Calculator

1. Enter the principal amount you’re starting with.
2. Enter the annual interest rate.
3. Enter the time period in years.
4. Choose how often interest compounds: annually, semi-annually, quarterly, or monthly.
5. See the maturity amount, principal and interest earned instantly, plus a year-wise breakdown.

What is a compound interest calculator?

A compound interest calculator projects how a one-time (lump-sum) investment grows when interest is added back to the balance at regular intervals, rather than paid out separately. Because each round of interest is calculated on a growing balance, the growth curve gets steeper the longer the money stays invested.

How compounding grows your money

Each time interest is added, it becomes part of your balance — so the next round of interest is calculated on a slightly bigger amount. That’s why compounding more often (say, monthly instead of yearly) adds up to a little more over time, even at the same interest rate.

Formula

A = P (1 + r/n)^(n×t)

Where P is the amount you start with, r is the annual interest rate, n is how many times a year interest is added, and t is the number of years.

Worked example

₹1,00,000 invested at 10% annual interest, compounded annually for 2 years, grows to ₹1,21,000 — ₹21,000 in interest.

Understanding your result

• Maturity amount is your principal plus all compounded interest combined.
• Interest earned is the growth on top of your original investment.
• The year-wise table shows the opening balance, interest earned and closing balance for each year.

Factors that affect the result

• Interest rate directly scales how fast your money grows.
• Time has an outsized effect since compounding accelerates the longer money stays invested.
• Compounding frequency has a smaller but real effect — more frequent compounding means slightly higher returns.

Common uses

This calculator is used to compare how different compounding frequencies affect the same investment, estimate the growth of savings or a lump-sum bonus, or double-check figures from a bank or investment product before committing.

Important notes & limitations

This is a mathematical projection based on a fixed rate you enter. It doesn’t account for taxes on interest, fees, or the fact that real investment returns (other than bank deposits) typically vary year to year rather than staying constant.