Compound Interest Calculator
Calculate compound growth with periodic or continuous compounding.
How to use this tool
- Enter initial balance, annual rate, years.
- Add monthly/periodic contributions (or none).
- Set compounding frequency.
- View final value, contributions invested, and interest earned.
How it works
Balance compounds with the standard formula; contributions earn compound interest from the date they're added. Results include a year-by-year table.
Tips
- Even small monthly contributions massively outgrow one-time deposits.
- Compounds are powerful because interest earns interest — start early.
- Compare daily vs annual compounding to see the small but real difference.
Limitations
Assumes a constant rate and no withdrawals; actual returns fluctuate.
Frequently asked questions
What is compounding frequency?
How often interest is added to the balance — annually, monthly, daily. More frequent compounding (holding rate constant) yields slightly more.
What's the formula?
A = P(1 + r/n)^(n·t), plus contributions for periodic deposits.
Can I include monthly contributions?
Yes — add a contribution amount and how often it's made.