What is compound interest?
Compound interest means earning returns on both your original capital and previous gains. Over long periods, this reinvested growth can become a major driver of portfolio value.
Calculator Guide
Compound Interest Calculator
Estimate how monthly contributions, annual return assumptions, and time can work together in a long-term investment growth calculator.
How compound growth works
The calculator projects growth from starting capital, recurring contributions, annual return assumptions, and monthly compounding. It is a model, not a prediction.
Monthly investing and compounding
A monthly compound calculator can show how regular contributions may build over time when combined with assumed investment returns.
Compound interest example
For example, an investor can compare different monthly contribution amounts and time horizons to understand how invested capital and growth may diverge.
Open the main calculator
Use the interactive DCA Backtest and Compound Interest Calculator to model your own monthly investment scenario.
Open the main calculatorDCA and Compound Interest FAQ
Is this a compound interest calculator for investments?
Yes. It is designed for educational investment growth scenarios using recurring contributions and assumed annual returns.
Does compounding guarantee future returns?
No. Market returns vary, and past or assumed performance does not guarantee future results.
Can I change the display currency?
Yes. The site supports multiple display currencies while keeping calculations internally based in USD.
Related guides
Continue with these related calculators and guides.
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Use the ETF comparison calculator to compare two ETF or stock DCA backtests with the same monthly amount, time period, display currency, and data-source warnings.
DCA vs Lump Sum
Compare dollar-cost averaging and lump sum investing using the same total contribution assumption, with educational notes on timing, emotion, fees, and risk.
Educational disclaimer
This page is for educational purposes only and is not financial advice. Past performance does not guarantee future results.