qcalculator.net

Investment Calculator

Project how an investment grows over time from a starting amount plus regular contributions. Adjust the return, time horizon and contributions to see the ending balance and how much of it is investment growth.

Your investment

Ending balance
$548,915
  • Initial
  • Contributions
  • Total return
Total invested
Total return
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How it works

The ending balance is the future value of the initial amount plus the future value of the contribution stream:

FV = P(1 + i)N + PMT × [ ((1 + i)N − 1) / i ]

Total return is the ending balance minus everything you put in.

Worked example

$10,000 to start, $500/month for 25 years at an 8% annual return:

Frequently asked questions

What return rate should I assume?
Historically, a broad US stock index has returned roughly 7–10% per year before inflation over long periods, though any given year varies widely and past performance doesn't guarantee future results. Many people model 6–8% for a stock-heavy portfolio and less for bonds. Use a conservative figure to avoid over-optimistic projections.
Does this account for inflation or taxes?
No — it shows nominal, pre-tax growth. To gauge real buying power, subtract your expected inflation rate from the return (e.g. use 5% instead of 8%). Taxes depend on the account type; tax-advantaged accounts like a 401(k) or IRA grow without annual tax drag.
How much does starting early matter?
A great deal. Because returns compound, contributions made early have decades to grow, so they typically contribute far more to the final balance than later ones. Even small amounts invested early can outpace larger amounts invested later.

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