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Tool 11 · Investment calculator

Grow a portfolio — minus the fees.

Project what a lump sum and steady contributions could become. Then see the quiet drag most people ignore: fees. A single percent, over decades, can cost you a fortune.

Portfolio value
$0

$10,000
$500
7%

Total return before fees, including reinvested dividends.

25
0.5%

Fund + platform costs. Index funds ~0.1–0.3%; many funds 1%+.

Final value
$0
You invested
$0
Growth
$0
Lost to fees
$0

Pro features. Step up contributions, see today's-money value, read insights, get the yearly schedule, compare fees and export.

Pro

Model it properly

Refine the model

0%

Invest a little more each year as your income grows.

0%

Adds a “real value” line in today’s prices.

Year by year

Compare fee levels

Yearly feeFinal valueLost to fees
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How the investment calculator works

The calculator compounds your starting amount and monthly contributions month by month at the return you choose, which represents your total return — capital growth plus reinvested dividends. It runs two projections at once: one at the full return, and one after subtracting your yearly fees. The gap between them is the money that quietly leaves your pocket, and over decades it's far larger than the headline fee suggests.

That's because fees compound too. A 1% annual fee doesn't cost you 1% of your gains — it's charged every year on your whole balance, so it steals a slice of growth that would otherwise have compounded for the rest of your life. That's why low-cost index funds are so powerful: keeping fees near zero can add years of retirement to the same set of contributions.

Most investment calculators flatter you by ignoring costs. This one deliberately puts fees front and centre, because they are the one variable you can control with certainty — you can’t command the market to return 8%, but you can choose a fund that charges 0.1% instead of 1%. That single decision, repeated for decades, is often worth more than years of extra saving. The two curves on the chart make the invisible drag visible.

A worked example

€10,000 start · €500/month · 7% return · 25 years · 0.5% annual fee

After fees the portfolio reaches about €425,000; with no fees it would have been roughly €462,000. That €37,000 gap is the lifetime cost of a "small" 0.5% fee — and it grows fast: a 1% fund would cost far more. The fee looks trivial each year, but it compounds against you for life.

Things to keep in mind

Frequently asked questions

What’s a reasonable fee to aim for?

Broad, low-cost index funds and ETFs commonly charge around 0.05–0.30% a year. Many actively managed funds charge 0.75–1.5% or more — and on top of that, platform fees may apply. Slide the fee down to those low levels and watch "lost to fees" shrink dramatically.

Is this the same as the compound interest tool?

They share the same engine, but this one focuses on investing — specifically the drag of fees and the difference between gross and net returns — while the compound interest calculator is the plain, fee-free version for understanding how growth works.

What return should I assume?

A globally diversified stock portfolio has historically returned roughly 7% a year after inflation over the long run, but any decade can differ widely. Use a figure you're comfortable with, and remember it's an estimate, not a promise.

Do small fees really matter?

Enormously, over time. Slide the fee from 0.2% to 1.0% and watch "lost to fees" jump — often into six figures on a lifetime of investing. It's the easiest big win in investing: choose low-cost funds.

Are dividends included?

Yes — the return you enter is a total return, so it already assumes dividends are reinvested. If you spend your dividends instead, use a lower return figure.