Stock Return Calculator

What is stock return calculator?

A stock return calculator projects how a stock investment grows over time, including the effect of an assumed annual return rate and any ongoing monthly contributions. It uses the same compound-growth math as a generic investment projection, but is framed around equity investing: you set an assumed annualized return (the long-run U.S. market average is roughly 10% before inflation, about 7% after), a starting principal, optional monthly purchases, and a holding period. The tool splits the final balance into the lump-sum portion and the contribution portion so you can see which source drove the growth. Use it to model a buy-and-hold scenario, to compare a lump sum versus dollar-cost averaging, or to bracket conservative 5% versus optimistic 10% market returns. Stocks are volatile year to year, so treat the projection as a long-run average, not a year-by-year forecast. The numbers run in your browser.

How to use this calculator

1. Enter your initial investment.
2. Enter your monthly contribution.
3. Enter your estimated annual return.
4. Enter your years to grow.
5. Click the "Calculate" button.
6. View your result instantly — the main result is displayed prominently at the top with a detailed breakdown below it.

When to use this calculator

• Projecting decades of buy-and-hold stock growth with dividends reinvested
• Comparing a one-time lump sum versus ongoing monthly contributions
• Bracketing conservative 5% versus optimistic 10% annualized returns
• Estimating how a 20- versus 30-year holding period changes the balance
• Modeling dollar-cost averaging over a long investment horizon