What does time do to my money?
Drop a starting amount, a monthly contribution, and how long you can wait. We'll show the part you put in and the part compounding made for you.
01Starting point
$
$/mo
02Return & horizon
%
yr
03 · Final balance · year 30
You'll have
$691k
Of which $190k is what you contributed and $501k is compounding doing the work.
What's in the pot27% you put in · 73% compound interest
You put in
$190k
Money multiplier
3.64×
Real value · today's $
$330k
Inflation eats
$362k
The story
Every dollar you invest becomes 3.64× over 30 years.
More than half of that growth happens in the final decade — that's compounding. Cutting the horizon to 20 years would leave you at $329k instead.
02 · The growth curve
The compounding gap widens with every year you wait
Stacked balance · 30 years
Compounded gains
Money you contributed
Year-by-year · select milestones
03 · Rate scenarios
What 3 percentage points actually mean
5% / yr
14.4yr to double$461k
2.43× · gains $271k
7% / yryour input
10.3yr to double$691k
3.64× · gains $501k
10% / yr
7.2yr to double$1329k
6.99× · gains $1139k
The spread
$868k
Same monthly contribution, same 30 years — but 10% vs 5% leaves $868k more on the table. Returns compound multiplicatively; small rate changes are huge over decades.
FIRE preview25× rule
If you spend $40k/yr in retirement
$1.0M target
At $500/mo and 7% return, your FIRE number ($1M) takes roughly 37 years from today.
Goal previewreverse the question
To hit $484k in 24 years at 7%
$579 /mo
Cut the horizon and you need much more per month — less time for compounding to help you.
After you start
Budget — find the $500
Money to invest comes from a budget. See where $500/mo can come from.
Open ↗Before you start
Debt payoff plan
Investing while paying 22.99% on a credit card is a losing trade. Clear high-APR debt first.
Open ↗Save your work