Investment Calculator
End balance with initial deposit, monthly contributions, return, and years.
Assumptions
Estimated balance:
You contribute: · Growth:
How the ending balance is built
Your initial investment compounds on its own for the entire period, while each monthly contribution starts compounding from the moment it's added — the calculator sums both effects month by month to reach the final balance, then reports how much of that total came from your own money ("contributed") versus market growth.
Frequently asked questions
Why does starting early matter so much? Because of compounding, contributions made early have far more time to grow than contributions made later — an extra 10 years of compounding at a typical stock market return can roughly double the eventual value of the same monthly contribution.
Is 7% a safe assumption for expected return? It's a commonly used long-run historical average for a diversified stock portfolio, but it's not guaranteed — actual annual returns vary widely, and a more conservative assumption is prudent for essential goals.
Does this account for taxes or investment fees? No — this is a gross growth projection. Taxes on gains (in a taxable account) and fund expense ratios would both reduce your actual take-home return.