Compound interest calculator: how compounding works
Compound interest is interest on interest. Each period, the interest earned is added to the principal, and the next calculation runs on the bigger total. Over years that snowball effect turns small savings into surprisingly large balances.
The inputs that drive growth
Interest is typically compounded daily, monthly or yearly. The more often it compounds, the faster the balance grows for the same rate. Rate, frequency and time work together — and time is the most underused ingredient of all.
- Principal — the money you save or owe at the start.
- Rate — the yearly interest percentage.
- Compounds per year — daily, monthly, quarterly or yearly.
- Years — the longer the period, the steeper the curve.
Compound interest on loans cuts the other way
The same mathematics steers loans and credit cards, where compounding increases what you owe. Term and rate decide how painful the curve gets; the Loan EMI Calculator shows the monthly payment so you can compare offers before signing.
Model any scenario with the calculator
The Compound Interest Calculator takes principal, rate, frequency and years, then shows the final balance and the growth curve. Run a couple of scenarios — a little more each month, a slightly higher rate — and let the snowball show you which lever matters most.