Your ETF’s factsheet says +9% a year — but you didn’t invest everything on day one, you drip-fed money in month after month. So what did your money actually earn? This calculator answers that with XIRR, the money-weighted annual return. List your deposits (and any withdrawals) with their dates, enter what the portfolio is worth today, and you get the single annual rate every euro you invested actually compounded at — usually a different number from anything your broker or fund publishes.
By Kestutis Balciunas · Last reviewed: 17 July 2026 · Figures and rules are 2026-vintage estimates — verify current data before acting. Educational tool, not advice.
Money-weighted vs time-weighted: two honest numbers that disagree
A fund factsheet reports the time-weighted return: what one euro invested on day one earned, with every period counted equally. It is the right way to judge the fund, because the manager doesn’t control when you add money. But it says nothing about you. The money-weighted return (XIRR — the same maths as Excel’s XIRR function) weights each period by how much of your money was actually in the market. If you invested €500 a month all year, most of your money only experienced the second half of the year — so a strong January helped you far less than the factsheet implies, and a strong December far more.
The formula, with a worked example
XIRR is the rate r that makes the net present value of all your cashflows zero: Σ CFi / (1+r)ti = 0, where each ti is the days since the first cashflow divided by 365, deposits count as negative cashflows and the current portfolio value as a final positive one. There is no closed-form solution, so the tool finds r numerically (bisection, 200 iterations — accurate to far more decimals than investing deserves).
Hand-checkable example: deposit €10,000 exactly one year ago, worth €11,000 today. The equation −10,000 + 11,000/(1+r) = 0 gives r = 10.00% — exactly the intuitive answer. Add a second deposit of €5,000 six months ago and the tool weights it by its half-year in the market, which no simple percentage can do.
Why savings-plan investors need this number
Anyone running a monthly plan — the approach we map out in building a portfolio with €500 a month — systematically bought at many different prices. In a rising market your XIRR will sit below the fund’s published return (your later euros had less time to grow); after a dip-and-recover, it can sit above it, because your mid-dip purchases were bargains. Neither gap means you did anything wrong. But XIRR is the number to compare against alternatives: if it persistently lags a savings account, something — usually fees, the drag we dissect in TER vs total cost of ownership, or bad timing habits — deserves a look.
For context: etf google sheet.
It is also the honest scoreboard for income strategies: dividends reinvested on many different dates are exactly the messy cashflow pattern XIRR was built for, which is why our dividend investing calculator models reinvestment the same way. And once you know your real historical rate, feed it into the compound growth calculator instead of a hopeful 8% — projections built on your own number are the ones worth trusting.
Reading your result
The tool shows the simple totals first — deposited, current value, gain in € and % — because the annualised figure can mislead over short spans (a +2% month annualises to +27%; the tool warns you below three months of history). Withdrawals are entered as negative amounts and handled correctly: money you took out early is no longer expected to earn anything. If the tool reports no solvable rate, the entries usually contradict each other — a withdrawal larger than everything ever deposited plus today’s value, or dates in the wrong order. Figures are illustrative, ignore taxes, and assume a 365-day year. Not financial advice.
These numbers make more sense with the guide
The free 12-page Starter Kit turns them into decisions: your first fund, a safe broker, and the tax basics for your country.
Frequently asked questions
Q: What is the difference between XIRR and my fund’s published return?
A: The fund publishes a time-weighted return: what one euro invested on day one earned. XIRR is money-weighted: it accounts for when each of your deposits actually entered the market. If you invested gradually, the two almost always differ — and XIRR is the one that describes your wealth.
Q: Why is my XIRR lower than my ETF’s performance even though I never sold?
A: In a steadily rising market, later deposits have less time to compound, which pulls your money-weighted return below the fund’s day-one figure. It is a mathematical consequence of drip-feeding, not a mistake — the same pattern flips in your favour when you keep buying through a dip.
Q: How do I enter withdrawals or sales?
A: Enter them as negative amounts on the date the money left the portfolio, e.g. -2000. The calculator treats them as cash returned to you, so they stop earning from that date. Dividends paid out to your bank account are withdrawals too; dividends reinvested inside the portfolio need no entry at all.
Q: How accurate is the result over short periods?
A: The maths is exact, but annualising a few weeks of performance produces silly numbers — a 2% first month annualises to over 25%. Below roughly three months of history, trust the euro gain instead; the tool shows a warning in that zone. XIRR becomes genuinely meaningful from about a year onward.
Q: Is this the same as the XIRR function in Excel or Google Sheets?
A: Yes — same definition, same result to several decimals. Enter deposits as negative numbers, the final value as positive, and Excel’s XIRR will confirm this tool. The calculator just saves you building the sheet, and gets the sign conventions right for you.