Investment Goal Calculator
Find out exactly how long it takes to grow your investment from one amount to another.
Milestones
| Milestone | Portfolio value | Time to reach |
|---|---|---|
| 25% of the way | $32,500 | 12yr 5mo |
| 50% of the way | $55,000 | 17yr 11mo |
| 75% of the way | $77,500 | 21yr 6mo |
| Goal (100%) | $100,000 | 24yr 2mo |
How the Time-to-Goal Is Calculated
This calculator works backwards from compound growth: given a starting amount, a target amount, an expected annual return, and an optional monthly contribution, it solves for the number of months needed to close the gap. Each month, your balance grows by the monthly-equivalent of your annual rate and your contribution is added, compounding on top of everything already there — the same mechanism behind the compound interest calculator, just run in reverse to find a time instead of a total.
A higher annual rate or a larger monthly contribution both shrink the time needed, but they don't trade off linearly — because of compounding, an extra few years of runway often does more work than doubling the monthly contribution amount.
Frequently Asked Questions
What return rate should I use?
That depends on what you're invested in. A diversified stock index has historically averaged close to 10% annually before inflation; bonds and cash typically return far less. Check the S&P 500 calculator for a rate derived from actual historical data instead of a guess.
Why does adding a monthly contribution change the timeline so much?
Regular contributions compound alongside your starting balance, so each dollar added earlier has more time to grow. Small, consistent contributions can shorten a multi-decade goal by years, especially at higher return rates.
What if my target can't be reached?
If the annual rate and monthly contribution are both too low relative to the gap between your start and target amounts, the calculator will flag that the goal isn't reachable under those assumptions — try raising the contribution or extending your expectations for the return rate.
Does this account for inflation?
No, all figures here are nominal. To see how inflation affects the real purchasing power of a target amount over time, use the portfolio calculator, which has an inflation-adjustment option.