Finance & Money

Compound Interest Calculator

Compound interest is interest calculated not just on your original principal, but on the interest that's already accumulated — which is what makes it grow faster than simple interest the longer money is left invested. This calculator works out the final amount and total interest earned on any principal, given an annual interest rate, a time period and a compounding frequency (yearly, half-yearly, quarterly or monthly).

It's useful for comparing fixed deposits, recurring investment products or loan products that quote compound rates, and for simply understanding how much of your eventual returns come from compounding versus your original deposit.

Principal (₹)

Annual interest rate (%)

Time period (years)

Compounding frequency

Enter values to see the compounded amount.

How to use the Compound Interest Calculator

Enter the principal amount you're starting with.
Enter the annual interest rate.
Enter the time period in years.
Choose how often interest compounds — yearly, half-yearly, quarterly or monthly — and view the final amount and interest earned.

The compound interest formula

A = P × (1 + r/n)^(n×t)

Where P is the principal, r is the annual interest rate (as a decimal), n is the number of times interest compounds per year, and t is the time in years.

Interest earned = A − P.

Frequently asked questions

How does compounding frequency affect the final amount?

The more frequently interest compounds, the higher the final amount for the same nominal annual rate — because interest starts earning its own interest sooner. Monthly compounding will always produce a slightly higher return than yearly compounding at the same stated annual rate.

What's the difference between compound interest and simple interest?

Simple interest is calculated only on the original principal for the entire period, so it grows linearly. Compound interest is recalculated on the growing balance (principal + accumulated interest) at each compounding period, so it grows faster the longer the money stays invested.

Can I use this for a recurring or fixed deposit?

Yes, for a fixed lump-sum deposit this formula matches how most banks calculate compound interest on fixed deposits. Recurring deposits, where you add money periodically, use a different formula (closer to the SIP formula) since new principal is added over time.