When evaluating the performance of an investment over multiple years, a single total return percentage can be misleading. An investment that returns 50% over five years performs very differently than one that returns 50% in a single year. Compound Annual Growth Rate (CAGR) solves this problem by expressing any multi-year return as a consistent annual rate.
What CAGR Represents
CAGR is the rate at which an investment would have grown each year if it grew at a constant pace. It smooths out year-to-year volatility and gives you a single number that represents the effective annual growth rate over the whole period.
This is useful because real investments do not grow at a constant rate — they may be up 20% one year and down 10% the next. CAGR lets you compare the overall performance of different investments on equal footing.
The CAGR Formula
CAGR = (Ending Value ÷ Beginning Value)^(1 ÷ Number of Years) − 1
Express the result as a percentage by multiplying by 100.
Worked Example
An investment grows from $5,000 to $8,500 over 6 years:
- CAGR = ($8,500 ÷ $5,000)^(1/6) − 1
- = (1.7)^0.1667 − 1
- = 1.0924 − 1
- = 9.24% per year
Even if the actual returns each year were +18%, −5%, +12%, +6%, +11%, and +9%, the CAGR of 9.24% gives you a single clean representation of overall performance.
Use the Investment Return Calculator to project growth at any assumed CAGR.
CAGR vs Average Return: An Important Difference
Average return and CAGR are not the same thing, and confusing them leads to overestimating actual performance.
Consider a $10,000 investment that gains 50% in year 1 and loses 50% in year 2:
- Year 1: $10,000 → $15,000 (+50%)
- Year 2: $15,000 → $7,500 (−50%)
- Arithmetic average return: (50% + (−50%)) ÷ 2 = 0%
- CAGR: ($7,500 ÷ $10,000)^(1/2) − 1 = −13.4% per year
The arithmetic average says you broke even. CAGR tells the truth: you actually lost money. This is why CAGR is the more accurate measure for evaluating investment performance.
Using CAGR for Comparisons
CAGR enables apples-to-apples comparisons between:
- Two funds held for different lengths of time
- A real estate investment vs a stock portfolio
- Your portfolio vs a benchmark index like the S&P 500
For reference, the S&P 500 has historically delivered a CAGR of approximately 7–10% over long periods (after inflation, closer to 5–7%). These are often used as benchmarks when evaluating portfolio performance.
Limitations of CAGR
CAGR is a useful summary metric, but it has limitations:
- It ignores volatility: Two investments with the same CAGR can have very different risk profiles
- It does not account for ongoing contributions or withdrawals: CAGR works for lump-sum investments; for regular contributions, you need IRR
- It can be misleading over short periods: A 3-year CAGR during a bull market looks very different from a CAGR that includes a major downturn
Practical Use in Financial Planning
When financial calculators ask for an "annual return" assumption, they are typically asking you to enter a CAGR. A conservative long-term assumption might be 5–6%, a moderate assumption 7%, and an aggressive assumption 9–10%. These projections are estimates, not guarantees.
Using CAGR to Compare Mutual Funds and ETFs
When comparing two funds, their 1-year returns can be very misleading due to market timing. CAGR over 5, 10, or 15 years gives a more meaningful comparison. A fund with a 15-year CAGR of 9% has outperformed one with a 15-year CAGR of 7% — even if the 7% fund had a better single year recently. Most fund screeners and financial websites report 3-year, 5-year, and 10-year CAGR by default for this reason.
Be cautious about comparing funds over different time periods. A fund with a 3-year CAGR of 18% may have benefited from exceptional market conditions during a bull run. Always look at longer periods that include both up and down markets.
Frequently Asked Questions
What is the difference between CAGR and IRR?
CAGR measures the growth of a single lump-sum investment over a period. Internal Rate of Return (IRR) handles cash flows that happen at different times — making it the right tool when you are investing or withdrawing money at various points, like with monthly 401(k) contributions. For a single lump-sum investment with no additional contributions or withdrawals, CAGR and IRR produce the same result.
What is a good CAGR for a stock portfolio?
The S&P 500 has historically returned approximately 10% annually in nominal terms (before inflation) and about 7% in real (inflation-adjusted) terms over long periods. An individual stock portfolio that achieves a 10–12% CAGR over 10+ years is considered strong performance. Below 6% (real) over the long run suggests underperformance relative to simply holding a broad index fund.
Can CAGR be negative?
Yes. If an investment loses value over the measurement period, the CAGR will be negative. For example, $10,000 that falls to $7,000 over 5 years has a CAGR of (7,000/10,000)^(1/5) − 1 = 0.896 − 1 = −10.4% per year. Negative CAGR is common for individual stocks that decline over time, or for any investment purchased near a market peak that is measured through a downturn.
Use the Investment Return Calculator with different CAGR assumptions to see how sensitive your retirement or savings projections are to the assumed return rate. Also check the Compound Interest Calculator for simpler growth modeling.