Calculators
Compound Interest Calculator
See how savings grow with compound interest, compounded yearly, half-yearly, quarterly or monthly, plus the effective annual rate.
About the Compound Interest Calculator
The Compound Interest Calculator shows how money grows when interest is added to the balance and then earns interest itself. Set a starting amount, an optional amount to add every month, the rate and the number of years, choose yearly, half-yearly, quarterly or monthly compounding, and a chart shows your money and the interest year by year.
What you can do with the Compound Interest Calculator
- Monthly top-ups: Add a regular amount on top of the starting sum.
- Four compounding options: Yearly, half-yearly, quarterly or monthly.
- Year-by-year chart: Your money and the interest it earns, stacked.
- Sliders and boxes: Drag or type every value.
Why compounding frequency matters
The more often interest is added, the faster the balance grows. 7% compounded quarterly is equivalent to about 7.19% compounded once a year, that's the "effective yearly rate" shown under the result. Most Indian bank fixed deposits compound quarterly, so the calculator starts on Quarterly.
Adding money every month
Use "Add every month" to model a recurring deposit, a monthly savings habit or topping up an investment. Each addition starts earning interest from the month it goes in, so early additions grow the most.
The rule of 72
To estimate how long money takes to double, divide 72 by the annual interest rate. At 8%, it takes about 9 years; at 6%, about 12. It's an approximation, but a surprisingly accurate one for typical rates.
What the calculator doesn't include
Real returns are reduced by tax on interest and by inflation, and investments like mutual funds don't grow at a fixed rate. Treat the result as growth before tax at a steady rate.
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Frequently Asked Questions
What's the compound interest formula?
A = P × (1 + r/n)^(n × t), where 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.
Can I add monthly deposits?
Yes. Set "Add every month" to the amount you'll add, and the result includes those deposits and the interest they earn.
How often do bank FDs compound in India?
Most banks compound fixed-deposit interest quarterly. Check your bank's terms, as some products differ.
How long does it take for money to double?
The Rule of 72 gives a quick estimate: divide 72 by the yearly rate. At 7% that is about 10.3 years. With quarterly compounding the exact figure is just under 10 years, which matches the default result of about 2 lakh from 1 lakh in 10 years.
Does monthly compounding earn much more than quarterly?
Not a lot at normal rates. 1 lakh at 7% for 10 years grows to about 1,96,715 compounded yearly, 2,00,160 quarterly and 2,00,966 monthly. Switch the Compounded option to compare, and see the effective yearly rate change.
What is the effective yearly rate?
It is the single yearly rate that gives the same growth once compounding is included: (1 + rate / n) to the power n, minus 1. A 7% rate compounded quarterly is 7.19% effective, and compounded monthly it is 7.23%.
How are monthly additions calculated?
Each monthly amount is added at the end of the month and earns interest from then on. Starting with 1,00,000 and adding 2,000 a month at 7% compounded quarterly for 10 years, you put in 3,40,000 and the final amount is about 5,45,560.
Is FD interest in India taxable?
Yes. FD interest is added to your income and taxed at your slab rate, and banks may deduct TDS once yearly interest crosses a threshold. The amounts here are before tax, so check with your bank or a CA for your situation.
How do I account for inflation?
Compare the rate with inflation. If an FD pays 7% and inflation is 6%, your money grows only about 0.94% a year in buying power. You can enter the rate minus expected inflation as a rough way to see growth in today's rupees.
Why does the final amount show L or Cr?
Large results are shortened using lakh (L) and crore (Cr) so they fit on screen, such as 2.00 L for about 2,00,000. Tap the Copy button to get the exact final amount and interest earned in full rupees.
Can I use this for a recurring deposit or SIP?
You can get a rough idea by setting the starting amount to 0 and entering the monthly amount, but banks calculate RD interest with their own quarterly rules, and SIP returns are not fixed. For SIPs, the site's SIP calculator is a better fit.
Read the guide
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