Millionaire calculator (how long until $1 million)
See how long your first million takes with your monthly contributions and compound interest. Example: $1,000 a month at 10% a year gets there in ~23 years.
Estimate with a constant rate, before taxes and inflation. To think in today's purchasing power, use a real (above-inflation) rate.
How the calculation works
We solve the compound-interest-with-contributions equation for time: n = log[(goal·i + PMT) ÷ (P·i + PMT)] ÷ log(1 + i), where P is the starting amount, PMT the monthly contribution and i the monthly rate.
In the default example ($10k + $1,000/mo at 0.8%/mo), the first million arrives in ~22 years — with interest contributing over $700k. Doubling the contribution cuts years; starting earlier cuts even more.
Examples
- $10k + $1,000/mo at 0.8%/mo: ~22 years to the first million.
- Doubling the contribution to $2,000/mo: drops to ~16 years.
Frequently asked questions
How much does $1 million yield per month?
It depends on the rate: at 0.8%/month, about $8,000/month gross. That is why the million is a passive-income milestone.
What if I raise contributions over time?
The time drops a lot — the calculator assumes a fixed contribution, so reality tends to beat the estimate if your income (and contribution) grows.
Does the amount account for inflation?
No — it is the nominal amount. A million in 20 years buys less than today. For purchasing power, use a real (inflation-adjusted) rate.
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Updated on July 4, 2026 · by Rafael Rossi · Methodology & sources