Compound Interest Calculator
Project investment growth with recurring contributions, a growth chart, and a year-by-year breakdown.
About this tool
Compound growth is easy to underestimate without running the numbers. Enter an initial investment, an optional monthly contribution, an annual interest rate, an investment length, and how often interest compounds (annually, quarterly, monthly, or daily), and this calculator projects your future balance, total contributions, and total interest earned.
A stacked-area growth chart visualizes contributions versus interest earned over time, and a full year-by-year breakdown table — downloadable as CSV — shows exactly how the balance builds each year.
Contribution timing
You can choose whether monthly contributions are added at the start or end of each month, which affects the total slightly since money added earlier has more time to compound.