How it works
A million is not a salary milestone; it is an arithmetic one, and this calculator shows the arithmetic. Give it your current savings, a monthly contribution and a return rate, and it compounds the balance forward month by month until it crosses the target — a million by default, but any number you set. The surprise is always the same: how much of the final sum is growth rather than contributions. Starting from $25,000 and adding $1,000 a month at 8%, the million arrives in about 26 years — but only $337,000 of it is money you put in; the other $663,000 is compounding doing the work. That is why the date responds so strongly to time and so weakly to heroic contributions late in the game. The tool also reports the monthly contribution that would reach the target in 30 years, which reframes the goal as a routine rather than a dream. Small increases matter more than they look — an extra $200 a month from the start can pull the date forward by years, because the earliest contributions compound the longest. Set the target to your own number and the lesson is identical.
Formula
Compound monthly: balance x (1 + r/12) + contribution, until balance >= target
Tips
- Most of a million is growth, not contributions — start early and let compounding work.
- An extra $200 a month from the start can pull the date forward by years.
- Use 7-8% for a diversified portfolio; 10% is the nominal historical average.
- Set the target to your own number — the arithmetic is the same for any goal.
- The earliest contributions compound the longest, so front-load when you can.
Frequently asked questions
- How long does it take to become a millionaire?
- It depends on savings, contributions and return. Starting with $25,000 and adding $1,000 a month at 8%, the million arrives in about 26 years. Raising the contribution or the return shortens it; starting earlier helps most of all because compounding has longer to run.
- How much do I need to invest monthly to reach a million?
- Over 30 years at 8%, roughly $670 a month from a standing start. The earlier you begin the less it takes each month, because the earliest contributions compound the longest. The calculator shows the exact monthly figure for your own timeline and return.
- How much of a million is growth versus contributions?
- Usually most of it is growth. In the $25,000 plus $1,000-a-month example, only about $337,000 of the final million is money you contributed — the other $663,000 is compounding. The longer the horizon, the larger the growth share becomes.
- What return should I assume?
- About 7-8% for a diversified stock portfolio after inflation is a reasonable planning figure; the nominal historical average is near 10%. A more conservative balanced portfolio argues for 5-6%. Treat the result as a plan, not a promise.
- Can I set a target other than a million?
- Yes — the target field takes any amount. Set it to $100,000 for a first milestone, $500,000 for a house, or $2 million for a fuller retirement. The arithmetic and the lessons are identical whatever the number.