Savings goals
See what a sum left untouched could grow to over the years.
Compound Interest Calculator
Enter the principal, rate and years and pick how often interest compounds.
Your files stay with you. Your files never leave your browser. This tool runs on your device: nothing is uploaded to our servers, so there is nothing for us to store or see.
How to use it
- Enter the principal, rate and time in years.
- Pick the compounding frequency.
- Read the maturity amount and the year-by-year table.
Where it helps
Compare schemes
Use the effective rate to compare offers that compound differently.
Learning
Show students how interest on interest builds up over time.
Good to know
Stays in your browser
Numbers you type are worked out on your device and never sent to our servers.
Time matters most
Years and the rate change the result far more than frequency.
Before tax
Interest may be taxable; this shows the gross amount.
Questions people ask
How do you calculate compound interest?
Compound interest uses Amount = P x (1 + r/n)^(n x t), where r is the yearly rate, n is how often interest is added and t is the years. Enter the principal, rate and years, pick yearly, half-yearly, quarterly, monthly or daily compounding, and read the maturity amount, the effective yearly rate and a year-by-year table.
- 5 Compounding options. Yearly to daily.
- ₹2,15,892 ₹1 lakh, 8%, 10 yrs. Yearly compounding.
- 8.30% Effective at 8% monthly. vs 8% yearly.
- Year table Balance by year. See it grow.
What is the compound interest formula?
Amount equals P times (1 + r/n) to the power of n times t. P is the principal, r is the yearly rate as a decimal, n is how many times a year interest is added and t is the number of years. ₹1,00,000 at 8% for ten years compounded yearly becomes about ₹2,15,892.
Does more frequent compounding help a lot?
A little. At 8% a year, monthly compounding gives an effective 8.30%, against 8% with yearly compounding. Daily compounding adds only a fraction more. The interest rate and the number of years make a far bigger difference than how often the interest is added. Try each option in the dropdown to see the gap yourself.
What is the effective yearly rate?
It's the single yearly rate that gives the same result as your chosen compounding frequency. A 7% rate compounded quarterly is effectively 7.19% a year. Comparing effective rates is the fair way to judge two deposits or loans that add interest on different schedules. The tool shows it next to the maturity amount.
How is compound interest worked out?
Subtract the principal from the maturity amount. If ₹1,00,000 grows to ₹2,15,892, the compound interest is ₹1,15,892. The tool shows both the maturity amount and the interest earned, and the year table shows how much interest had built up by the end of each year.
How long does it take to double my money?
A quick rule is to divide 72 by the yearly rate. At 8% money roughly doubles in nine years, at 12% in six years. Try it here by entering a principal and rate and adjusting the years until the maturity amount is about twice what you started with.
Why does the year table matter?
It shows the balance and the total interest at the end of each year. The early years look slow, then growth speeds up as interest earns interest. Seeing that curve helps explain why leaving money untouched for longer pays off much more than chasing a slightly higher rate.
Which compounding option should I pick for a bank FD?
Most Indian banks compound FD interest quarterly, so choose Quarterly. Savings accounts usually credit interest quarterly as well. Some company deposits and bonds compound half-yearly or yearly. If you aren't sure, the deposit's terms or the bank's rate page will say. The FD calculator uses quarterly by default for this reason.
Can I use it for a loan?
It shows how a sum grows when no repayments are made, which suits a deposit or an unpaid debt. Most loans are repaid in EMIs, so the interest is worked out on a falling balance. Use the loan prepayment calculator for an EMI loan instead of this tool.
How does inflation affect compound growth?
Prices also rise each year, so the buying power of your maturity amount is lower than the figure suggests. To see the real growth, subtract an inflation figure from the rate, such as 8% minus 5%, which gives 3%, and calculate again for a fair comparison.
What is the difference between nominal and effective rates?
The nominal rate is the headline figure, such as 8% a year. The effective rate includes the extra growth from compounding during the year, such as 8.30% with monthly compounding. Loan offers usually quote the nominal rate, so always compare the effective rates. The tool shows the effective rate for you.
How many years can I enter?
Up to 100 years. Long periods are useful for showing how small amounts grow over a lifetime, for example a sum saved at a child's birth. For real plans, keep to the period you'll actually stay invested and use a cautious rate, because rates change over time.
Is compound interest taxable?
Interest from deposits is usually added to your income each year and taxed at your slab rate, even if you don't withdraw it. Some schemes, such as PPF, are tax-free under current rules. This tool shows the gross amount before any tax is taken off.
Is anything I enter stored?
No. The maths runs in your browser and nothing is sent to our servers. There's no sign-up and the page saves nothing after you close it. You can try as many principals, rates and compounding options as you like, and nobody else sees the figures.
Does it work on a phone?
Yes. The fields bring up the number keypad, the compounding choice is a dropdown and the table scrolls sideways on a narrow screen. It works in any mobile browser, so you can check an offer from your bank or a scheme while you're reading it.
Is the compound interest calculator free?
Yes, it's free with no sign-up and no limit. It sits alongside the simple interest, FD, RD and SIP tools among the free finance calculators from Marketiism. Marketiism builds business software and doesn't sell deposits, loans or investment products. Use it as often as you like for study, savings or planning.
Want this inside your own account?
Marketiism keeps your invoice numbers, GST reports, UPI payment links and WhatsApp reminders in one place. Leave your details and we'll call to set it up for your business, or start the trial yourself.
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