Compound Interest Calculator
See how a starting amount and regular deposits grow with compound interest — set your rate, term and how often it compounds to get the future balance and the interest earned.
These results are estimates for learning and planning only — not investment, financial or tax advice. They assume a steady rate and regular deposits, and leave out inflation, taxes and fees, so real returns will differ.
Year-by-year growth
| Year | Deposited | Interest | Balance |
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Every calculation runs in your browser — the amounts you enter never leave your device.
FAQ
How is the balance worked out?
Your starting amount grows by compound interest for the whole term, and each regular deposit is added and then compounds as well. The future balance is those two parts together; the interest earned is the balance minus everything you paid in.
What does the compounding frequency change?
It sets how often interest is added and how often your deposit goes in. Compounding monthly instead of yearly grows the balance a little faster at the same rate, and your deposit counts as that period’s amount — per month, per quarter, and so on.
When are the deposits counted?
Each deposit lands at the end of every compounding period, so the first one starts earning from the next period, while the starting amount earns from the outset. Set the deposit to zero to see growth from the starting amount alone.
Can I rely on this for real decisions?
Treat it as an estimate for learning and rough planning, not advice. It assumes one steady rate for the whole term and leaves out inflation, taxes, fees and market swings, so a real account will differ — check with a licensed professional before deciding.