Compound Interest Calculator
Compound or simple interest with regular contributions, and a year-by-year schedule.
Final balance
1,418,345
| Year | Balance | Interest |
|---|---|---|
| 1 | 1,035,567 | 35,567 |
| 2 | 1,072,399 | 72,399 |
| 3 | 1,110,541 | 110,541 |
| 4 | 1,150,039 | 150,039 |
| 5 | 1,190,943 | 190,943 |
| 6 | 1,233,301 | 233,301 |
| 7 | 1,277,166 | 277,166 |
| 8 | 1,322,591 | 322,591 |
| 9 | 1,369,631 | 369,631 |
| 10 | 1,418,345 | 418,345 |
Compounding frequency is the part that surprises people
Simple interest accrues on the principal alone, so the balance grows in a straight line. Compound interest accrues on the balance, so each period earns interest on the interest before it — the curve everyone has seen.
How often that happens matters more than it looks. The same nominal 5% compounds to a different total annually, monthly and daily, which is exactly why lenders and savings products quote an effective annual rate alongside the nominal one.
Regular contributions
A contribution added each period is counted as money you put in, not as interest earned — the schedule separates the two so the return is not flattered by your own deposits.
Frequently asked questions
Is inflation accounted for?
No. Every figure is nominal. A real return would need an inflation assumption, which is a forecast rather than arithmetic.
What currency is this in?
None. The numbers are unitless, so use whatever currency you like as long as you are consistent.