How to Invest to $1 Million — Compound Interest Calculator
Want to reach a $1 million portfolio? This calculator shows the monthly contribution, time, and return rate needed to hit that milestone.
Compound Interest
How It Works
At 8% annual returns, $1,000/month grows to $1 million in roughly 24 years. Without compounding, it would take 83 years of straight contributions.
Start with even $20k principal and you can reach $1M faster — that initial $20k alone grows to ~$137k at 8% over 25 years.
The math behind becoming a millionaire is simple: consistency × time × a reasonable return. You don't need to be lucky — just patient.
Maxing a 401(k) (~$1,875/month in 2024) with a 7% return hits $1M in about 21 years. Add the employer match and it's even faster.
Frequently Asked Questions
How long to invest $1,000/month to reach $1 million?
Approximately 24 years at 8% returns, 26 years at 7%, or 21 years at 10%. The earlier you start, the shorter the runway needed.
How much do I need to save monthly to be a millionaire?
At 7% returns over 30 years, just $820/month reaches $1M. Over 20 years, you'd need $1,920/month. Time does most of the work.
Is $1 million enough to retire on?
Using the 4% rule, $1M provides ~$40k/year in retirement income. Combined with Social Security, it's sufficient for many retirees in moderate-cost areas.