Free interactive tool
Compound Growth Visualizer
See what you contributed — and what compounding quietly added on top.
Watch money grow — and see what actually grew
Set a starting amount, a monthly habit, a rate, and time. The chart splits what you contributed from what compounding added.
Time is the strongest slider in this model: the growth share widens in the last years, not the first ones, which is why starting early beats starting big.
- Set years to 5, then to 25, and compare the growth share.
- Halve the monthly amount but double the years — better or worse?
- Set the rate to 0 to see what saving alone does.
Compound growth pays interest on interest, so the curve leaves the straight contribution line further behind every year. The split matters: the chart shows exactly how much of the final balance you deposited and how much time added.
Time is the strongest slider here. Halving the monthly amount but doubling the years usually wins — which is the whole argument for starting early.
Why does starting early matter so much?
The final years of compounding do the heaviest lifting, and only an early start buys them.
Is the model exact?
It compounds monthly at a steady rate — real returns vary year to year, so treat it as a planning shape, not a promise.