Compound Interest Calculator
Compound interest calculator: enter principal, annual rate, years and compounding frequency to see future value and total interest earned. Free and instant.
- 100% free
- No sign-up
- Private: runs on your device
- Updated
Your result
Your result, a full breakdown and charts appear here as you type.
How this was calculated
What is the Compound Interest Calculator?
The Compound Interest Calculator shows how a one-time deposit grows when interest is added back to the balance and starts earning interest itself. Enter the starting principal, the nominal annual rate, the number of years and how many times a year interest is compounded, and you get the future value plus the total interest earned.
It suits anyone comparing fixed deposits, recurring bank offers, bonds or loan quotes that state a nominal rate with monthly, quarterly or yearly compounding. Indian bank FDs, for instance, commonly compound quarterly, so you would enter 4. The model assumes a fixed rate and no further deposits or withdrawals, which keeps the answer clear and easy to compare across offers.
How to use the Compound Interest Calculator
- Enter the amount you invest today in Starting principal, for example 100000.
- Enter the quoted yearly rate in Nominal annual rate (%), such as 7.5.
- Enter the investment period in Years. Decimals like 2.5 are allowed.
- Enter Compounds per year (1–365): 1 for yearly, 4 for quarterly, 12 for monthly, 365 for daily.
- Press Calculate to see the Future value, with the Interest earned shown below it.
- Copy the result or press Reset to compare a different rate or frequency.
Key features
- Future value and total interest shown together
- Any whole-number compounding frequency from 1 to 365 per year
- Fractional years supported, up to 1000 years
- Rates from 0% to 10000% accepted
- Results in rupees and paise with Indian digit grouping, plus one-click copy
Why use this compound interest calculator
- Compare FD or savings offers with different compounding
- See how much of the final balance is pure interest
- Understand the effect of time on growth
- Private, quick estimates with no sign-up
Formula used
Future value = P(1 + r/n)^(n×years); interest = future value − P.
Compound Interest Calculator examples
Bank FD with quarterly compounding
Input: Starting principal 100000, Nominal annual rate 7.5, Years 5, Compounds per year 4
Result: Future value: 1,44,994.80
Interest: 44,994.80
₹1 lakh grows to about ₹1.45 lakh, earning roughly ₹44,995.
Same deposit with yearly compounding
Input: Starting principal 100000, Nominal annual rate 7.5, Years 5, Compounds per year 1
Result: Future value: 1,43,562.93
Interest: 43,562.93
Yearly compounding earns about ₹1,432 less than quarterly.
Long-term monthly compounding
Input: Starting principal 500000, Nominal annual rate 8, Years 10, Compounds per year 12
Result: Future value: 11,09,820.12
Interest: 6,09,820.12
₹5 lakh more than doubles to about ₹11.1 lakh.
Important notes before you rely on the result
- Projections assume a constant rate of return every period. Real mutual fund, stock and deposit returns go up and down, so treat the figures as illustrations, not promises.
- Taxes (such as capital gains tax or TDS on interest), exit loads, expense ratios and inflation are not deducted unless you build them into the rate you enter.
- Past returns do not guarantee future returns. For investment decisions, read the scheme documents and consult a SEBI-registered adviser.
Compound Interest Calculator: frequently asked questions
What is the compound interest formula?
Future value = P × (1 + r/n)^(n × t), where P is the principal, r the nominal annual rate as a decimal, n the compounding periods per year and t the number of years. Interest earned is the future value minus P. For ₹1,000 at 12% compounded monthly for 2 years, the calculator shows Future value: 1,269.73 and Interest: 269.73.
What compounding frequency should I enter for a bank FD?
Use the frequency stated by your bank. Most Indian bank fixed deposits compound quarterly, so enter 4. Enter 12 for monthly, 2 for half-yearly, 1 for yearly and 365 for daily. The rate you enter should be the nominal annual rate the bank quotes, which the calculator divides by your chosen frequency.
Does this calculator include TDS, tax or inflation?
No. It shows gross growth at a fixed rate. Interest on FDs is taxable in India and banks may deduct TDS, and inflation reduces what the money will buy in future. Treat the result as an estimate for comparison, not a guarantee or financial advice; check the actual terms with your bank or a qualified advisor.
Can I add monthly deposits to the compound interest calculation?
Not in this tool. It models a single starting amount with no further deposits or withdrawals. If you plan to invest a fixed sum every month, use the SIP calculator, which adds up equal monthly contributions. For a one-time investment where you know the effective yearly return rather than a nominal rate, the lumpsum calculator fits better.
What is the difference between simple and compound interest?
Simple interest is earned only on the original principal, while compound interest is also earned on the interest already added. Over short periods the gap is small, but it widens with time. ₹1 lakh at 7.5% for 5 years earns ₹37,500 simple interest, versus about ₹44,995 when compounded quarterly.
How is the result rounded?
Amounts are shown to 2 decimal places with Indian digit grouping, so ₹1 lakh at 7.5% compounded quarterly for 5 years appears as 1,44,994.80. The calculation itself runs at full precision before this display rounding. Banks also apply their own rounding at each compounding step, so a bank statement may differ from this estimate by a few rupees.
Results are estimates for general information, not financial, medical, legal, tax, or property advice. Confirm important figures with the relevant institution or a qualified professional.