CAGR Calculator

What Is CAGR and Why It Beats "Average Return"

CAGR stands for compound annual growth rate. It answers one question: if your investment had grown by exactly the same percentage every single year, what would that percentage be?

That sounds like a simple average. It is not, and the difference is where most people get fooled. Imagine an investment that gains 50% one year and loses 50% the next. The simple average is 0% — you broke even, apparently. The reality: €10,000 becomes €15,000, then €7,500. You lost 25%. The CAGR is −13.4%, and it is the honest number.

This is why arithmetic averages flatter volatile assets so badly. Any time returns swing around, the simple average overstates what you actually earned. CAGR does not, because it is built from where you started and where you ended — the only two facts that pay your bills.

The CAGR Formula

The CAGR formula is short enough to run in your head at a push:

CAGR = (Ending value / Starting value)^1/years − 1

Turn €10,000 into €25,000 over 8 years and you get (25000/10000)^(1/8) − 1 = 12.1%. Note what it ignores: everything that happened in between. A smooth climb and a terrifying rollercoaster with identical endpoints produce identical CAGRs.

CAGR vs Total Return

Total return in that example is 150%. It sounds vastly better than 12.1%, and it is the number people quote when selling you something. But 150% over 8 years and 150% over 30 years are wildly different outcomes. CAGR is what makes them comparable — it is a rate, not a total.

Where CAGR Quietly Misleads You

CAGR has real blind spots, and knowing them is the difference between using it and being used by it.

It hides volatility completely. Two investments with a 10% CAGR can have wildly different paths — one steady, one halving twice along the way. If you had to sell during a crash, your real outcome bears no resemblance to the CAGR.

It ignores contributions. If you added money along the way, CAGR between the start and end values is meaningless — the growth includes your deposits. For that, use our compound interest calculator, which handles regular contributions properly.

It is a nominal number. A 7% CAGR while inflation runs at 4% is really about 3% of purchasing power. Our inflation calculator shows how much that gap eats over a decade.

It says nothing about fees. A fund reporting 8% CAGR gross and charging 1.5% delivers 6.5% to you. Over 30 years that gap is not 1.5% — it is roughly a third of your final wealth.

Using CAGR Properly

Use it to compare, not to predict. It is the right tool for asking "did this fund actually beat that index?" over the same window. It is the wrong tool for assuming the next decade repeats the last one.

Pair it with the years-to-double figure above, which comes from the same maths as the Rule of 72: divide 72 by your CAGR for a quick mental estimate. At 12%, roughly six years. At 6%, twelve. That single comparison explains why small differences in annual return compound into enormous differences in outcome.

And be honest about the window you choose. Measuring from the bottom of a crash to the top of a boom produces a spectacular CAGR that tells you nothing. Cherry-picked start dates are the oldest trick in performance marketing.

Worked Examples: What Different CAGRs Actually Do

Percentages are abstract until you watch them run. Take €10,000 left alone for 30 years:

• At a 3% CAGR it becomes about €24,300 — you roughly doubled, and inflation probably ate most of it.
• At a 7% CAGR it becomes about €76,100 — more than seven times your money.
• At a 10% CAGR it becomes about €174,500 — seventeen times.

Look at that spread again. The gap between 7% and 10% is not "three percentage points" — it is €98,000 on the same starting capital. This is the single most important thing CAGR teaches: the rate is not a linear dial, it is an exponent. Small edges compound into different lives.

Why This Makes Fees So Expensive

Now run it backwards. If the market delivers 8% and your fund charges 1.5%, your CAGR is 6.5%. Over 30 years, €10,000 grows to about €66,100 instead of €100,600. That 1.5% did not cost you 1.5% — it cost you roughly a third of your final wealth. The fee is charged on your whole balance every year, so it compounds against you exactly as returns compound for you.

CAGR vs IRR: Which One Do You Need?

If your money went in as a single lump and came out as a single lump, CAGR is the right tool. If you contributed or withdrew along the way, you need IRR (internal rate of return), which weights each cash flow by when it happened.

The practical rule: buying once and holding — use CAGR. Paying in monthly — use IRR, or model it directly with a compound interest calculator that handles contributions. Using CAGR on a portfolio you have been feeding every month will flatter your performance badly, because it credits the investment with growth that was really just your own deposits.

This tool is educational and not personalised financial advice. Past growth rates never guarantee future ones.