Reverse the math

How Much to Invest Monthly

Start from the number you want to reach. See the monthly amount it takes, how much growth does for you — and what waiting costs.

$
yrs
$
%
After fees
6.86% a year
VWRA default: 7% a yearA round planning assumption, not a guaranteed or historical figure.
Subtract fund feesVWRA TER 0.14% a year
My goal is in today's moneyGrow the target with inflation
Currency

You need to invest

VWRA · 6.86% net
$596/month

to reach $500,000 in 25 years with VWRA

You'd pay in
$183,842
Growth does the rest
$316,158

63% of the goal would come from growth.

If returns are different

Lower · 4%
$966/mo
Base · 7%
$596/mo
Higher · 10%
$341/mo

Path to your goal

Hover or tap the chart for any year
VWRA balanceYour contributions
$0$150k$300k$450k$600kNowYr 2Yr 4Yr 6Yr 8Yr 10Yr 12Yr 14Yr 16Yr 18Yr 20Yr 22Yr 25Goal $500k

Assumes monthly compounding at a constant rate, with contributions at the end of each month. Educational estimate only: real returns vary, and taxes and trading costs change results.

The cost of waiting

Same goal, same deadline, starting later
StartMonthly neededTotal you pay inExtra vs starting now
Now$596$183,842—
In 1 year$648$191,763+$7,921
In 3 years$771$208,462+$24,620
In 5 years$922$226,345+$42,503
In 10 years$1,508$276,524+$92,682

Assumes what you've already invested keeps growing while you wait.

How this calculator works

Most investment calculators ask what your money will grow to. This one runs the math backwards: you set the goal and deadline, and it solves for the monthly contribution. It first works out how far your existing investment will grow on its own, then finds the monthly amount that closes the gap.

The formula

PMT = [Goal − P × (1 + r)n] × r ÷ [(1 + r)n − 1]
r = (annual return − fee) ÷ 12 · n = years × 12

Popular goals at 7% a year

GoalTimelineMonthly needed
$100,00010 years$578
$500,00025 years$617
$1,000,00020 years$1,920
$1,000,00030 years$820

Starting from zero, before fees and taxes. Not adjusted for inflation.

Making the number smaller

  • Start earlier. The cost-of-waiting table shows how quickly delay adds up.
  • Extend the deadline. A few extra years can cut the monthly amount sharply.
  • Keep fees low. A cheaper fund means less of your return is taken each year — compare ETF fees.
  • Use what you have. Even a modest existing balance lowers the monthly amount, because it compounds the whole time.

Frequently asked questions

How much do I need to invest monthly to become a millionaire?

At an assumed 7% a year, starting from zero, about $820 a month for 30 years, or about $1,920 a month for 20 years. The shorter your timeline, the more of the work your own contributions have to do.

How much should I invest each month to reach $100,000?

Starting from zero at 7% a year, roughly $578 a month gets you to $100,000 in 10 years. Enter your own timeline and what you already have above.

What does 'my goal is in today's money' do?

Prices rise over time, so $500,000 in 25 years will buy less than $500,000 today. With this switched on, the calculator grows your target by inflation first, so the monthly amount reflects what you'd actually need.

Why does waiting a few years cost so much?

Money invested early has the longest time to compound. Delay the start and the remaining years must be covered by bigger monthly payments — and more of your own money in total.

What return should I assume?

There is no right answer. The defaults are round, conservative planning figures. Check the lower scenario: if you can afford that monthly amount, you have a cushion if markets disappoint.