Support: Compound Interest Calculator

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Common questions

What is compound interest?

Interest earned on your original money and on the interest already added to it. The longer the money stays, the faster it grows.

How do I calculate compound interest?

A = P × (1 + r/n)^(n × t). For $10,000 at 5% compounded monthly for 10 years: 10,000 × (1 + 0.05/12)^120 = $16,470.09, of which $6,470.09 is interest.

What is APY?

Annual percentage yield: the yearly rate once compounding is counted. 5% compounded monthly is an APY of about 5.116%. Comparing APYs tells you which account really pays more.

Does compounding daily make much difference?

A little. At 5%, daily compounding gives an APY of about 5.127% against 5.116% monthly. The rate and the time matter far more.

How is a fixed deposit's interest worked out in India?

Most banks compound FD interest quarterly. ₹1 lakh at 7% for five years compounded quarterly grows to about ₹1,41,478. Use the FD shortcut for these settings.

Are monthly additions included?

Yes. Each addition is treated as made at the end of the month and earns interest from then on.

Is tax included?

No. Interest is usually taxable; the figures here are before tax.

Is it free?

Yes, completely free, with no sign-up.