Historical Investment & Stock Market Education · 13 of 20
What Is CAGR and How Does It Work?
2026-10-21 · 917 words · 4 min read · Nottinvested
CAGR is the constant yearly rate that would take you from start to finish if the path were smooth. Markets are not smooth. Here is how to read the number Then & Now prints.
- what is CAGR
- CAGR how does it work
- compound annual growth rate explained
- CAGR vs absolute return
- stock CAGR calculator
- 10 year CAGR
CAGR means compound annual growth rate. It answers: if this holding had grown at one steady yearly rate, what rate would turn the starting lump sum into the ending value over this many years? It is a smoother. It is not a salary. It is not what happened in any particular year. Then & Now prints CAGR next to the multiple because people otherwise compare a 10-year 150 percent pile-up to a 7 percent deposit as if they were the same shape.
The formula is (ending divided by starting) raised to (one divided by years), minus one. If 10,000 became 31,000 in 10 years, CAGR is about 12 percent. The third year might have been minus 20. The eighth might have been plus 40. CAGR will not tell you that. The timeline will.
What CAGR hides
It hides sequence. It hides drawdowns. It hides that a handful of months can carry a decade. It hides that you might have sold in the hole and never earned the printed CAGR. How fear stops people from investing, in the regret series, is partly a CAGR problem: the number looks like a deposit, the path does not feel like one.
It also hides extra deposits. CAGR on a lump-sum reconstruction assumes one start and one end. Your SIP is not that. Do not paste a lump-sum CAGR onto a monthly plan and call it a forecast.
CAGR is the constant rate that would have produced this ending if reality had been polite. Reality was not polite.
CAGR is not the average of yearly returns
The arithmetic average of 10 yearly returns is a different statistic and can sit above CAGR when volatility is high. Volatility drags geometric (compounded) growth below the arithmetic mean. That is why a wild stock can have flashy average years and a less flashy CAGR. If someone quotes “average return” without saying which average, ask.
- Holding-period return: total percent over the whole window.
- CAGR: annualised, as if smooth.
- Yearly returns: the actual jagged list.
- Multiple: ending divided by starting (2×, 5×).
Then & Now shows multiple, percent profit, and CAGR together so you do not have to guess which one you are looking at. Price as of a date still sits beside them. A 12 percent CAGR with a 345 dollar print and 378 shares is a holding. A 12 percent CAGR with no units is a slogan.
What if you had invested?
Then & Now calculator
What if you had invested? Price a lump sum, then keep reading “What Is CAGR and How Does It Work?.”
Loading calculator…
Not advice. Disclaimer · All essays
How to use CAGR without worship
Use it to compare windows of similar length, in the same currency, with the same reinvestment rule. Do not use it to rank “best stocks” off a feed of survivors. Do not use it as a promised future rate. Historical CAGR is an ex-post summary. The inflation essay later in this series asks you to subtract a rough inflation rate if you care about real growth. Even then you are describing the past.
If two tickers have the same CAGR and very different timelines, they were not the same experience. Open both timelines. The one with a 50 percent hole asked more of your stomach. CAGR equalised them after the fact, which is exactly why it is both useful and misleading.
Worked sense-check
10,000 to 13,000 in 10 years is a modest CAGR, about 2.7 percent — cash-like, with equity drama. 10,000 to 130,000 in 10 years is about 29 percent — extraordinary, lumpy if it happened, not a template. Run those ideas as real listings on notinvested.com between this page and compound growth. You will see that CAGR is the headline and share count is the plot.
What is CAGR and how does it work? It compresses a jagged holding-period return into a yearly rate as if compounding had been even. Use it as a caption. Use the calculator as the film. Then read how compound growth builds wealth, which is the story CAGR is trying to summarise — including why the last years on a long path carry more dollars than the first.
Compare like with like
A 5-year CAGR and a 20-year CAGR are different products. A rupee CAGR and a dollar CAGR are different products. A total-return CAGR and a price CAGR are different products. Then & Now’s number is the owner ending you chose, annualised over years held. Write those conditions when you quote it. Unlabelled CAGRs are how deposits get unfairly mocked and how legends get unfairly copied.
If a CAGR makes you want to buy the name today, pause. That number is ex-post. The next essays on compound growth and total return explain the engine and the scoreboard. The regret series already warned you about turning a caption into a chase. Use the calculator, read the hole, then decide whether your surplus’s job can survive a hole like that. CAGR cannot decide it for you.
A final caution: a high CAGR on a short window is often a spike. A modest CAGR on a 20-year window that includes two holes is often a life. Prefer the second as a teacher even when the first photographs better. Then & Now lets you pick 5, 10, 15, or 20 years for that reason. Pick more than one window on the same ticker before you let CAGR talk.
When a slide shows 25 percent CAGR, ask for the start date, the end date, and whether dividends are in. If the presenter cannot answer, the slide is theatre. Then & Now answers all three for a lump sum you actually type. Prefer that over a slide you cannot interrogate.
Previous
How Stock Splits Affect Historical Investment Returns
Next
How Does Compound Growth Build Wealth?
Education only — not a recommendation to buy, hold, or sell any security. Past paths on the Then & Now calculator are reconstructions, not forecasts. See the disclaimer.