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Investment Growth Visualizer

See exactly how your money compounds over time. Watch contributions stack against growth to understand the true power of long-term investing.

Investment Details
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$0$500K
$ /mo
$0$5K
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years
1 yr50 yrs

Contributions vs Growth

Portfolio Value Over Time

Guide

How to Use the Investment Growth Visualizer

This tool shows you exactly how a portfolio grows over time by separating what you put in (contributions) from what the market gives back (growth). Here's how to get an accurate picture.

Enter your initial investment

This is the lump sum you're starting with today — a brokerage balance, an inheritance, or simply $0 if you're starting from scratch and plan to build up entirely through monthly contributions.

Set your monthly contribution

Enter how much you plan to add every month. Consistent contributions — even modest ones — are one of the biggest drivers of long-term growth thanks to dollar-cost averaging.

Choose an expected annual return

Use a realistic long-term average for your asset mix — see the FAQ below for typical ranges. Small changes here compound into large differences over long time horizons, so it's worth testing a few scenarios.

Set your time horizon

Enter how many years you plan to keep investing. Longer horizons dramatically amplify the effect of compounding — the chart makes this visible as the growth curve steepens in later years.

Read the charts and export

The stacked bar chart splits your final balance into contributions vs. investment growth, and the line chart tracks portfolio value year by year. Click "Download PDF" to save a copy of your projection.

Math

How Investment Growth Is Calculated

This visualizer combines two separate growth calculations: how your initial lump sum compounds on its own, and how your stream of monthly contributions compounds as each one is added.

FV = P × (1 + r/n)n×t + PMT × (((1 + r/12)12t − 1) ⁄ (r/12))

FV = future value of the portfolio

P = initial investment (lump sum)

PMT = monthly contribution

r = expected annual return (as a decimal)

n = compounding frequency per year (12 for monthly)

t = number of years

Why the split between contributions and growth matters

Two portfolios can reach the same final balance in very different ways. One might get there mostly through your own deposits; another might get there mostly through market growth compounding on itself. Seeing the stacked bar chart split out "contributions" from "growth" makes it clear how much of your future balance is money you actually saved versus money the market earned for you — and that ratio shifts dramatically the longer your time horizon stretches.

The power of starting early

Because growth compounds on growth, money invested in your first few years has far more time to multiply than money invested in your last few years — even if the total amount contributed is identical. This is why the portfolio-value line typically looks almost flat for the first several years and then curves sharply upward later on: the base of compounded growth needs time to build before its effect becomes visually dramatic. Try shortening the time period in the calculator above to see how much less pronounced that curve becomes.

If you want to model a single lump sum with no ongoing contributions, see the Compound Interest Calculator. If you're working backward from a target amount, the Savings Goal Calculator tells you exactly how much to contribute each month to get there.

FAQ

Frequently Asked Questions