Compound Interest Calculator
See how an initial amount grows over time with compound interest.
This tool provides mathematical projections for illustration purposes only and is not financial advice or a guarantee of investment returns.
| Years | Balance |
|---|---|
| 1 | $10,512 |
| 5 | $12,834 |
| 10 | $16,470 |
| 15 | $21,137 |
| 20 | $27,126 |
| 25 | $34,813 |
| 30 | $44,677 |
Frequently asked questions
What is compound interest?
Compound interest is interest calculated on both your original amount and any interest already earned, so your money grows faster over time compared to simple interest, which only applies to the original amount.
How does compounding frequency affect the result?
More frequent compounding (daily vs. annually, for example) results in slightly higher returns, since interest gets added to your balance more often and starts earning its own interest sooner.
Does this account for regular contributions?
No — this calculator shows growth from a single initial amount only. Adding regular monthly contributions would increase the final balance further, since each new contribution also earns compound interest for the time it's invested.
Is this a guarantee of investment returns?
No — this is a mathematical projection assuming a constant, fixed interest rate. Real investments typically fluctuate and involve risk; this tool is for illustration and planning purposes only.
How much will $10,000 grow to in 10 years at 5% interest?
With monthly compounding at 5% annual interest, $10,000 grows to about $16,470 after 10 years — see the chart above for other timeframes.
What is the rule of 72?
The rule of 72 is a quick way to estimate how long it takes money to double: divide 72 by the interest rate. At 5%, that's about 14.4 years — which roughly matches what this calculator shows for a 5% rate over that period.
Does compounding monthly make a big difference vs annually?
It helps, but not dramatically at everyday rates — $10,000 at 5% for 10 years grows to about $16,470 compounded monthly versus about $16,289 compounded annually, a difference of roughly 1%. The gap widens more at higher rates or over longer time periods.
About this tool
This calculator shows how an initial amount grows over time with compound interest, using the standard compound interest formula A = P(1 + r/n)^(nt). Adjust the compounding frequency to see how it affects long-term growth.