What Is CAGR and How Is It Calculated?
Understand Compound Annual Growth Rate (CAGR), why it outperforms arithmetic average return, and how to apply the formula.
Table of Contents
Why Average Return Can Be Deceptive
Imagine investing $1,000. In Year 1 your portfolio gains +100% to $2,000. In Year 2 your portfolio falls -50% back down to $1,000.
The simple arithmetic average return is (+100% - 50%) / 2 = +25% per year. Yet you have made $0 in actual profit! CAGR eliminates this distortion by measuring true geometric compounding.
The CAGR Mathematical Formula
CAGR = (Ending Value / Beginning Value)^(1 / Number of Years) - 1.
CAGR tells you the constant annual rate of growth that would have taken you from the starting balance to the final balance over that period.
A Worked Example
Suppose an investment grows from $10,000 to $16,000 over four years. Plugging into the formula: CAGR = (16,000 / 10,000)^(1/4) - 1 = (1.6)^0.25 - 1 ≈ 0.1247, or about 12.47% per year. That single figure represents the smooth annual rate that would carry $10,000 to $16,000 in four years, regardless of how bumpy the actual year-by-year path was.
This smoothing is exactly why analysts prefer CAGR for comparing investments with different holding periods. Two funds with wildly different annual swings can be compared fairly on a single like-for-like growth rate.
What CAGR Does Not Tell You
CAGR is powerful but incomplete. Because it only looks at the start and end points, it hides volatility entirely — a steady 12% grower and a violently swinging investment can share the same CAGR while being very different risks. It also ignores any cash flows added or withdrawn along the way, which is why it suits a single lump-sum investment better than an account you contribute to regularly.
Use CAGR as a headline comparison figure, but pair it with a measure of volatility and an honest look at the year-by-year returns before drawing conclusions. It answers "how fast did this grow on average?" — not "how risky was the ride?"
Put this guide into practice
CAGR Calculator
Calculate Compound Annual Growth Rate (CAGR) over multiple investment years.
ROI Calculator
Calculate Return on Investment (ROI) percentage and annualized return rate.
Compound Interest Calculator
Calculate compound growth over time with customizable compounding frequencies and regular deposits.
Frequently Asked Questions
Why is CAGR better than a simple average return?
Simple averages ignore compounding and can be badly misleading — a +100% year followed by a -50% year averages to +25% but produces zero actual profit. CAGR measures true geometric growth from start to end.
Does CAGR account for money I add over time?
No. CAGR only uses the beginning and ending values, so it fits a single lump-sum investment. For accounts with ongoing contributions, a money-weighted return measure is more appropriate.