Compound Interest Calculator
Project how a balance grows over time, with or without regular contributions, at any compounding frequency. Shows the year-by-year balance and how much of the total is interest rather than deposits.
Compound Interest Calculator
Final balance
1,136,694
You put in
700,000
Interest earned
436,694
Effective rate
8.30%
per year, after compounding
| Year | Paid in | Interest | Balance |
|---|---|---|---|
| 1 | 160,000 | 10,550 | 170,550 |
| 2 | 220,000 | 26,955 | 246,955 |
| 3 | 280,000 | 49,701 | 329,701 |
| 4 | 340,000 | 79,316 | 419,316 |
| 5 | 400,000 | 116,369 | 516,369 |
| 6 | 460,000 | 161,477 | 621,477 |
| 7 | 520,000 | 215,309 | 735,309 |
| 8 | 580,000 | 278,589 | 858,589 |
| 9 | 640,000 | 352,101 | 992,101 |
| 10 | 700,000 | 436,694 | 1,136,694 |
How to use it
- Enter your starting amount and the annual interest rate.
- Set how often interest compounds — monthly is the common default for savings accounts.
- Add a regular contribution if you plan to keep paying in, and set how often.
- Set the number of years, then read the final balance and the split between what you put in and what the interest added.
- Compare the effective annual rate to the headline rate: more frequent compounding makes the real return slightly higher.
Frequently asked questions
- What is the difference between simple and compound interest?
- Simple interest is charged only on the original amount. Compound interest is charged on the balance including interest already earned, so the growth accelerates over time.
- Does compounding frequency matter much?
- Less than people expect. At 10% a year, monthly compounding beats annual by about half a percentage point of effective rate. The rate and the time horizon matter far more.
- Does this account for inflation or tax?
- No. It projects nominal growth only. Real purchasing power will be lower, and any tax on interest reduces it further — subtract both before treating the final figure as spendable.
Related tools
- Loan and EMI CalculatorFind the monthly instalment on any loan and see the full repayment schedule, month by month, with interest and principal split out.
- Percentage CalculatorWork out a percentage of a number, what share one number is of another, or the change between two values. Shows the working. Runs in your browser.
Built and maintained by Kavitha Kanchana
Software engineer at Cortana AI and co-founder of Ryzera Technologies, based in Sri Lanka. Found a bug or a wrong number? Email me.