Investment returns get reported in all sorts of ways ? some more flattering than others. "Average annual return of 15%" sounds impressive. But if an investment gained 50% one year and lost 20% the next, its average return is 15% ? yet you'd actually have less money than a 10% CAGR would have produced. The average is technically correct and practically misleading.
CAGR ? Compound Annual Growth Rate ? cuts through this. It tells you the single steady annual return that would have taken you from your starting value to your ending value over a given period. It's the only apples-to-apples way to compare investments with different time horizons and volatility profiles.
The CAGR Formula
Example: $10,000 grows to $18,500 over 7 years
CAGR = (18,500 / 10,000)^(1/7) − 1 = 1.85^0.1429 − 1 = 9.18%
In plain English: what single annual growth rate, compounded every year for the full period, would turn your starting amount into your ending amount? Use our CAGR Calculator to compute this instantly for any investment.
Why Simple Averages Mislead
Here's the core problem with arithmetic averages. Suppose an investment returns +50% in year 1 and −33% in year 2:
| Year | Return | Value of $10,000 |
|---|---|---|
| Start | — | $10,000 |
| Year 1 | +50% | $15,000 |
| Year 2 | −33% | $10,050 |
- Arithmetic average return: (+50% − 33%) ÷ 2 = +8.5%/year
- CAGR: ($10,050 / $10,000)^(1/2) − 1 = +0.25%/year
The arithmetic average says 8.5%. The CAGR says 0.25%. Your actual experience was a near-zero return. CAGR tells the truth; the average flatters the investment.
CAGR vs. Average Return: A Realistic Comparison
| Investment | Reported Avg. Return | Actual CAGR | $10,000 After 10 Years |
|---|---|---|---|
| High-volatility fund | 12% | 9.1% | $23,800 |
| Low-volatility fund | 10% | 9.6% | $25,100 |
The higher-advertised-return fund actually produced less money. This is why CAGR matters for comparing funds, strategies, and investment products.
How to Use CAGR to Compare Investments
Comparing investments over different time periods
Investment A doubled over 8 years. Investment B tripled over 14 years. Which performed better annually?
- Investment A CAGR: (2.0)^(1/8) − 1 = 9.05%
- Investment B CAGR: (3.0)^(1/14) − 1 = 8.03%
Investment A, despite a smaller total gain, outperformed annually. Without CAGR, the comparison is meaningless.
Evaluating a business or asset
CAGR is widely used in business to measure revenue, earnings, or valuation growth over time. A company that grew revenue from $2M to $8M over 6 years has a revenue CAGR of (8/2)^(1/6) − 1 = 26%.
Benchmarking against an index
If the S&P 500's 10-year CAGR is 10.5% and your portfolio's 10-year CAGR is 8.2%, you've underperformed the index by 2.3 percentage points annually ? compounded over a decade, that's a substantial difference in ending wealth.
What CAGR Doesn't Tell You
CAGR is powerful but not complete. It has important blind spots:
- It hides volatility ? Two investments with identical CAGRs can have wildly different year-to-year experiences. One might be a smooth ride; the other a roller coaster.
- It assumes a lump sum ? CAGR measures a single starting investment to a single ending value. If you made contributions along the way, CAGR doesn't reflect your actual return. Use IRR (Internal Rate of Return) for that.
- It's backward-looking ? Past CAGR doesn't predict future performance. A 10-year CAGR reflects history, not a guarantee.
- It ignores taxes and fees ? A fund with a 10% CAGR but a 1.5% annual fee and high tax drag may produce a much lower after-tax, after-fee CAGR.
CAGR and the Rule of 72
CAGR connects directly to the Rule of 72: divide 72 by a CAGR to get the approximate number of years to double. A 9% CAGR doubles your money in roughly 8 years. A 6% CAGR takes 12 years. This makes CAGR immediately intuitive ? not just a percentage, but a doubling clock. See The Rule of 72 Explained for a full walkthrough.
Calculate CAGR for Any Investment
Enter a starting value, ending value, and number of years in the CAGR Calculator to get the compound annual growth rate instantly.