Compound Interest Calculator
See how your principal plus monthly contributions grow over time.
How it works
1Enter your principal and monthly contribution
2Enter your expected annual return and time horizon
3See total value, profit, and a year-by-year chart
COMPOUND GROWTH SLIP
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Total contributed--
Total profit--
Estimated using monthly compounding. Actual returns fluctuate with the market — for planning purposes only, not investment advice.
AD SLOT
How does compound interest work?
Compound growth comes from reinvesting each period's earnings back into the principal, so future returns are calculated on a growing base. Combined with steady monthly contributions, the effect becomes much more powerful the longer your time horizon. This tool compounds monthly: interest is applied first, then that month's contribution is added.