Added at the end of each month. Use 0 for none.
Show year-by-year breakdown
| Year | Total contributed | Total interest | Balance |
|---|---|---|---|
| 1 | 12,400.00 | 801.42 | 13,201.42 |
| 2 | 14,800.00 | 1,834.27 | 16,634.27 |
| 3 | 17,200.00 | 3,115.28 | 20,315.28 |
| 4 | 19,600.00 | 4,662.39 | 24,262.39 |
| 5 | 22,000.00 | 6,494.83 | 28,494.83 |
| 6 | 24,400.00 | 8,633.24 | 33,033.24 |
| 7 | 26,800.00 | 11,099.74 | 37,899.74 |
| 8 | 29,200.00 | 13,918.03 | 43,118.03 |
| 9 | 31,600.00 | 17,113.55 | 48,713.55 |
| 10 | 34,000.00 | 20,713.58 | 54,713.58 |
How to use the Compound Interest Calculator
- 1Enter your initial deposit and the amount you plan to add each month (use 0 if none).
- 2Enter the expected annual interest rate as a percentage and the number of years.
- 3Choose how often interest compounds: Annually, Semi-annually, Quarterly, Monthly or Daily.
- 4Review the Final balance, Total contributions and Total interest earned.
- 5Scroll through the year-by-year table to see how your balance builds over time.
How compound interest works
With simple interest (see the simple interest calculator), you earn interest only on the money you originally put in. With compound interest, the interest you earn is added to your balance, and in the next period you earn interest on that interest as well. Over long periods this snowball effect becomes the main source of growth.
Time matters more than almost anything else. The longer money stays invested, the more compounding periods it goes through, which is why starting early with small amounts can outperform starting later with larger ones. Interest builds up on borrowed money too, and the loan EMI calculator shows how much a loan costs over its tenure.
Compound interest formula
For a single deposit, the future value is A = P(1 + r/n)^(nt), where P is the starting amount, r is the annual rate as a decimal, n is the number of compounding periods per year and t is the number of years. For example, 10,000 at 5% compounded annually for 10 years grows to about 16,288.95. Compounded monthly, the same deposit reaches about 16,470.09, and compounded daily about 16,486.65.
This calculator also adds your monthly contributions, which are treated as deposits made at the end of each month. Each contribution then earns interest for the remaining time. Total contributions are your initial deposit plus all monthly deposits, and total interest earned is the final balance minus total contributions.
Example with monthly contributions
Imagine you start with 10,000, add 200 every month, and earn 7% a year compounded monthly for 10 years. You contribute 34,000 in total (10,000 plus 120 deposits of 200). The final balance comes to about 54,713.58, meaning roughly 20,713.58 of it is interest.
The year-by-year table makes the pattern clear: in the early years most of the growth comes from your own deposits, while in later years the interest earned each year becomes larger and larger. If you invest a fixed amount in a fund each month, the SIP calculator runs a similar projection.
The rule of 72
The rule of 72 is a quick mental shortcut for estimating how long it takes money to double. Divide 72 by the annual interest rate: at 8%, money doubles in about 72 ÷ 8 = 9 years; at 6%, in about 12 years. It works best for rates between roughly 4% and 12% and assumes no additional contributions.
You can check the estimate with this calculator by entering a deposit, no monthly contribution, and a rate, then finding the year in the table where the balance passes twice the starting amount.
Learn more
Frequently asked questions
Does compounding frequency make a big difference?
It makes some difference, but less than the interest rate or the time invested. Moving from annual to monthly compounding increases the result modestly, and moving from monthly to daily adds very little. The rate and the number of years have a much larger effect.
What interest rate should I use?
Use the rate your savings account or deposit actually pays, or a conservative long-term estimate for investments. Investment returns are not guaranteed and vary from year to year, so the result is a projection rather than a promise. To compare two rates or returns in relative terms, the percentage calculator can help.
Are contributions added at the start or end of each month?
This calculator assumes monthly contributions are made at the end of each month. Deposits made at the start of the month would earn slightly more because each one would earn interest for one extra month.
Does the calculator account for taxes or inflation?
No. The results show nominal growth before taxes, fees and inflation. To get a rough inflation-adjusted figure, you can subtract the expected inflation rate from the interest rate you enter.
Is my data stored or shared?
No. All calculations happen in your browser and nothing you enter is uploaded or saved. You can find related savings and loan tools in the finance calculators section.