How Long Until Your Fund Reaches Its Goal?
Investing a fixed amount every month lets compounding work in your favor — over time, your balance grows faster than your contributions alone. This calculator takes your monthly contribution, expected annual return, and target amount, then estimates how many months it will take to reach that goal. It assumes you invest at the end of each month and reinvest all returns, using a simplified monthly-compounding model that doesn't account for real-world market volatility.
How the Math Works
The annual return is converted into a monthly rate, and the calculator solves for the number of months needed using the future value of an annuity formula. A higher assumed return shortens the time to your goal, but it also comes with more risk of losing principal, so it's worth weighing both sides. Setting the return to 0% shows how long it would take by saving alone, with no investment growth.
Raising your monthly contribution shortens the timeline noticeably for the same goal. You can also work backward — pick a timeline first, then adjust the target or contribution to see what's realistic. Try both a conservative and a slightly higher return assumption to get a feel for the likely range.
Frequently Asked Questions
Many investors conservatively assume 6-8% a year for stock funds and 3-5% for bond-heavy funds. Future returns are never guaranteed, so compare a few assumptions.
This assumes a constant monthly return, so it's an estimate only. Real market swings can make the actual time longer or shorter.
※ This is an estimate for reference only and doesn't account for taxes, fees, or return volatility.