Compound Interest Calculator
Project how a savings or investment balance grows over time with regular contributions, at any compounding frequency. Calculations run in your browser; nothing you enter is sent anywhere.
Compound interest calculator FAQs
What does compounding frequency mean?
It's how often interest is calculated and added to your balance. More frequent compounding (daily vs. annually) earns slightly more at the same nominal interest rate, because interest starts earning its own interest sooner.
How are regular contributions handled?
This calculator adds your contribution once per compounding period selected — for example, once a month if you choose monthly compounding. Interest is credited first, then the contribution is added, so a new contribution doesn't start earning interest until the following period.
Is this the same as a retirement or investment calculator?
It's the same underlying math (compound interest with regular contributions), but this tool assumes a fixed, known interest rate throughout — real investments fluctuate. Use it to understand mechanics and compare scenarios, not as a guarantee of investment returns.