FT MarketWatch

Investment Growth Calculator

Written by Greg, founder of FTMarketWatch — a former licensed commodities trader, self-directed investor since. Not a licensed financial advisor.

What this tool does: estimates how your money could grow over time based on a starting amount, regular monthly contributions, your time horizon and an assumed average annual rate of return.

Enter your assumptions

$
What you already have invested or plan to invest as a lump sum.
$
How much you plan to add each month.
How long you expect to leave the money invested.
%
This is a simplifying assumption, not a prediction.

This calculator is for educational illustration only. Actual returns will vary, and no future performance is guaranteed.

How to interpret the numbers

The main takeaway from this kind of calculation is usually not the exact dollar amount, but the relationship between time, contributions and return assumptions.

  • On Dollar-Cost Averaging we look at how regular contributions help smooth the ride.
  • On Asset Allocation we discuss how your stock/bond mix influences the kinds of returns – and volatility – you might experience.
  • On Investing 101 we put these pieces together into a simple, written plan.

Use this calculator as a rough map, not a precise forecast. If changing one input (such as saving a little more each month) materially changes the outcome, that can be a useful planning insight even though no one knows future returns exactly.