Why compound annual growth rate (CAGR) matters to a first-time founder
Investors, market reports and pitch decks quote growth as CAGR, so you need to read it correctly and calculate your own the same way. If you simply average your yearly growth rates instead, you will overstate growth whenever the years differ, and an investor who reruns the numbers will notice. It also helps you test market claims: a market growing at 25% a year compounded roughly triples in five years.
Examples of compound annual growth rate (CAGR)
Revenue grows from €200,000 to €450,000 over three years. Divide the end value by the start value to get 2.25, take the cube root (about 1.31) and subtract one: CAGR is about 31% a year. The actual years might have been +100%, −10% and +25%, taking revenue to €400,000, €360,000 and €450,000. Averaging those three rates gives 38%, which overstates the real growth.
Common misunderstanding
CAGR is most often confused with the average annual growth rate, which has its own page. That measure simply averages each year’s percentage change and ignores compounding, so it comes out higher whenever growth is uneven. The other trap is reading CAGR as a forecast. It describes the past, or the assumption behind a projection, and one unusually strong or weak year at either end can swing it a lot.
When to use it
Use it whenever you compare growth across periods longer than a year, such as revenue over three years in a pitch deck or a market forecast in your business plan, and always state the start and end years. For month-to-month tracking in an early startup, monthly growth rate is more useful, because a CAGR built on one or two years of data says little.