Compound Interest
Compound Interest Calculator
Calculate compound interest and the final amount from principal, rate, time and compounding frequency.
How the calculator works
Compound interest adds earned interest back to principal so later periods earn on a larger base. More frequent compounding produces a slightly higher effective yield at the same stated annual rate.
Compound interest formula
A = P × (1 + r / n)^(n × t)
P is the principal, r is the annual rate, n is compounding frequency per year, and t is time in years. Interest earned is A − P.
Example
₹10,000 at 10% for 2 years, compounded annually, becomes ₹12,100. Interest is ₹2,100. Monthly compounding for the same headline rate finishes a little higher because interest is credited twelve times a year.
Important considerations
Stated rates, effective annual rates and APR are not interchangeable. Read the product sheet. This page is a mathematical illustration, not a bank or fund quote.
Frequently asked questions
What is the difference between this and the FD calculator?
The formula is the same family. The FD page is worded for bank deposits and omits daily compounding. This page is the general compound-interest identity, including daily compounding.
Does daily compounding assume 365 days?
Yes. Some money-market conventions use 360 days. If a product specifies 360, the result here will be a close illustration rather than an exact match.
Can I add yearly contributions?
Not on this page. For recurring contributions use SIP, RD or PPF. This calculator is for a single principal.
Related calculators
- Lumpsum CalculatorProject the growth of a one-time investment at an expected annual return.
- FD CalculatorEstimate fixed deposit maturity value based on compounding frequency.
- CAGR CalculatorMeasure the compounded annual growth rate between a starting and ending value.
- SIP CalculatorEstimate the future value of monthly systematic investments, with an optional annual step-up.
Browse the full directory on the calculators page.
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SmartCalculators provides educational calculators and estimates. Results are for informational purposes only and should not be considered financial, tax, investment, legal or professional advice.