Millionaire Calculator — Time to Reach $1 Million
Enter your monthly savings, expected annual investment return, and starting balance to find out how long it takes to reach your target — $1 million or any other amount. The growth curve shows how compound returns accelerate wealth over time.
$
%
$
$
Time to reach target at current savings rate and return
- 1
Monthly interest rate
7% ÷ 1,200 = 0.005833Annual rate converted to a monthly compounding rate. - 2
Adjusted target
1,000,000 + 1,000 ÷ 0.005833 = 1,171,429 - 3
Adjusted balance
10,000 + 1,000 ÷ 0.005833 = 181,429 - 4
Months to target
ln(1,171,429 ÷ 181,429) ÷ ln(1 + 0.005833) = 321 - 5
Years to target
321 ÷ 12 = 26.8
How does this calculator work?
n = log[(T + PMT/r) / (PV + PMT/r)] / log(1+r) where r = annual rate ÷ 1,200, PMT = monthly contribution, PV = current savings, T = target. At 7%/year with $1,000/month from $10,000, you reach $1 million in about 28 years. All inputs are editable.
Formula
How this is calculated
This calculator uses the future-value formula for regular contributions into a compounding account. Each month, the existing balance earns one month of the annual rate (r/12), and a fixed contribution (PMT) is added. Setting FV = T and rearranging gives n = log[(T + PMT/r) / (PV + PMT/r)] / log(1+r), where r is the monthly rate, PV is the starting balance, and T is the target. For a zero return rate, the formula simplifies to n = (T − PV) / PMT.
The annual return rate is the assumed investment growth rate, not a bank deposit rate. The S&P 500 has returned roughly 7% per year after inflation (real) and ~10% nominal on a historical average. Future returns are not guaranteed; this is a planning tool, not a forecast. A 1–2% change in the assumed rate can shift the timeline by several years — always test sensitivity by adjusting the rate.
Total gains = final balance minus total cash invested. Over long timelines, investment gains typically dwarf contributions — the classic power of compound growth. Halving the savings period (by starting earlier or saving more) can reduce the contributions needed substantially.
Frequently asked questions
At 7% annual return starting from zero: $500/month takes ~40 years; $1,000/month ~30 years; $2,000/month ~24 years; $3,000/month ~20 years. Starting with existing savings shortens the timeline — adjust the "current savings" field to see the effect.
The S&P 500 has historically returned ~10% nominal and ~7% real (inflation-adjusted) per year on a long-run average, though individual decades vary widely. Use 5–6% for a conservative diversified portfolio, 7–8% for a broad equity index, 9–10% for an optimistic scenario. Do not use nominal rates without remembering that inflation erodes purchasing power.
No. It assumes all growth compounds tax-free (as in a Roth IRA or ISA). For taxable accounts, reduce the rate by your effective tax on gains. It also uses nominal dollars — a $1 million target in 30 years will have less purchasing power than $1 million today due to inflation.
Also known as
TG we-Calculate Editorial Team. (2026). Millionaire Calculator — Time to Reach $1 Million [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/millionaire-calculator
TG we-Calculate Editorial Team. "Millionaire Calculator — Time to Reach $1 Million." TG we-Calculate. 2026. https://we-calculate.com/calculator/millionaire-calculator.
TG we-Calculate Editorial Team, "Millionaire Calculator — Time to Reach $1 Million," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/millionaire-calculator
@misc{wecalculate_millionaire_calculator, title = {Millionaire Calculator — Time to Reach $1 Million}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/millionaire-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?