Compound interest calculator
Enter a starting amount, a monthly deposit, an annual rate and a number of years to see how interest earns interest over time.
- Total deposited
- $53,000
- Interest earned
- $42,770
Yearly schedule
| Year | Total deposited | Interest earned | Balance |
|---|---|---|---|
| 1 | $7,400 | $312 | $7,712 |
| 2 | $9,800 | $762 | $10,562 |
| 3 | $12,200 | $1,358 | $13,558 |
| 4 | $14,600 | $2,107 | $16,707 |
| 5 | $17,000 | $3,018 | $20,018 |
| 6 | $19,400 | $4,098 | $23,498 |
| 7 | $21,800 | $5,356 | $27,156 |
| 8 | $24,200 | $6,801 | $31,001 |
| 9 | $26,600 | $8,443 | $35,043 |
| 10 | $29,000 | $10,292 | $39,292 |
| 11 | $31,400 | $12,358 | $43,758 |
| 12 | $33,800 | $14,652 | $48,452 |
| 13 | $36,200 | $17,187 | $53,387 |
| 14 | $38,600 | $19,974 | $58,574 |
| 15 | $41,000 | $23,026 | $64,026 |
| 16 | $43,400 | $26,358 | $69,758 |
| 17 | $45,800 | $29,982 | $75,782 |
| 18 | $48,200 | $33,915 | $82,115 |
| 19 | $50,600 | $38,172 | $88,772 |
| 20 | $53,000 | $42,770 | $95,770 |
Estimates for information only. They are not financial advice.
How it works
- Interest is added at the compounding frequency you choose.
- Monthly deposits are added at the end of each month.
- The result is a projection, not a promise: real returns vary.
Guide
What compound interest means
Compound interest means you earn interest on your original money and on the interest already earned. The longer the money stays invested, the faster it grows, because each period builds on a larger balance. This is why starting early matters more than most people expect.
The effect of time and regular contributions
Time is the strongest factor. The same monthly contribution grows far more over 30 years than over 10. Regular contributions add fresh money that also compounds. Try changing the number of years and the monthly amount to see which has the bigger effect.
How often interest is added
Interest can be added yearly, quarterly, monthly or daily. More frequent compounding gives a slightly higher result for the same annual rate, but the difference is small compared with the rate itself and the time invested.
A note on real returns
This tool assumes a constant rate. Real investments vary from year to year, and inflation and fees reduce what you actually keep. Treat the result as an illustration, not a forecast.
Frequently asked questions
What is compound interest?
Compound interest is interest calculated on your initial amount and on the interest already earned. The longer you leave the money, the faster it grows.
Does the compounding frequency matter?
It matters a little. More frequent compounding gives a slightly higher result, but the rate and the number of years have a much bigger effect.