Calculate compound interest
See how a lump sum grows with compounding, at any frequency, over any period.
The starting amount and annual interest rate.
Annually, semi-annually, quarterly, or monthly.
The final amount, and how much of it is interest.
Frequently asked
How is compound interest calculated?
Using A = P(1 + r/n)^(nt), where P is the principal, r is the annual rate, n is the number of compounding periods per year, and t is the time in years.
Why does compounding frequency matter?
More frequent compounding (e.g. monthly vs. annually) means interest starts earning interest sooner, so the same nominal rate produces a slightly higher return the more often it compounds.
How is this different from the FD or RD calculators?
This uses a generic principal-and-rate formula for any lump-sum investment. FD and RD Calculators are tailored to how Indian banks structure those specific deposit products, including their typical quarterly compounding.
Does it account for tax on the interest earned?
No, this shows the gross maturity value before any tax. Interest income is generally taxable; check the rules that apply to your situation.
Can I compare monthly vs. annual compounding side by side?
Not in a single view. Change the compounding frequency and re-run the calculation to compare each option's result.
What's a realistic interest rate to use?
Use the actual rate quoted by your bank or investment product rather than a rough estimate. Small rate differences compound meaningfully over long periods.