Investment Calculator
Project how a portfolio could grow from a starting amount and regular contributions, and what it would be worth in today’s money.
Projected value in 20 years
$428,090
- In today’s dollars
- $261,251
- Total contributed
- $186,222
- Investment growth
- $241,868
- Growth multiple
- 2.30×
Portfolio growth
Explain my numbers
Get a plain-English reading of the result above: what drives it, what the trade-offs are and what to ask a lender or adviser. It is educational, not financial advice. Only these inputs and results are sent, and nothing is stored.
How the projection works
The calculator adds your contribution each month and grows the balance by one twelfth of your annual return, compounded monthly. Contributions rise once a year by the percentage you set. The “today’s dollars” line divides each year’s value by (1 + inflation)year.
A steady return is a simplification. Real markets go up and down, and the order of returns matters most when you are adding or withdrawing large amounts, which is why the retirement calculator looks at the drawdown years separately.
Frequently asked questions
How much will my investment be worth?
Enter a starting amount, how much you add each month, an expected annual return and a time frame. The calculator compounds monthly and shows the result both in future dollars and in today’s dollars after inflation.
What return should I assume for stocks?
Long-run US stock market returns have averaged roughly 10% a year before inflation, or around 7% after, over the past century, but with large swings. Many planners use 5–7% for a cautious projection. Bonds and cash have historically returned less.
Why show the result in today’s dollars?
Because $1 million in 30 years will not buy what $1 million buys today. Dividing by (1 + inflation)^years converts the future balance into today’s purchasing power, which is the more useful number for planning.
What does increasing contributions each year do?
It models raising your deposits as your income grows, say 3% a year. It often has a surprisingly large effect over long periods.
Beginning vs end of month: does it matter?
Investing at the start of each month gives every deposit one extra month of growth. Over decades that adds a little under one month’s return to the result.