The Calmar Ratio: Return Relative to Maximum Drawdown
By return alone, A and B are both 10% per year, but A got cut in half along the way while B barely shook—are they really the same investment? The Calmar Ratio puts exactly this "how rough the road was" into the return and tells you in a single number.
What Is the Calmar Ratio?
The Calmar Ratio is the "average annual return" divided by the "maximum drawdown (MDD)." Simply put, it measures "how much I earned each year relative to the biggest decline I experienced."
The formula is very simple.
Calmar Ratio = average annual return (CAGR) ÷ maximum drawdown (MDD)
For example, if an asset produced a 12% average annual return but at one point fell to a maximum of -30%, the Calmar Ratio is 12 ÷ 30 = 0.4. Conversely, if it's 12% a year but the maximum drawdown was only -6%, it's 12 ÷ 6 = 2.0. Even for the same return, the side that shook less scores much higher.
The maximum drawdown (MDD) is the largest fall from peak to trough. If you're unsure what maximum drawdown is, looking at the crisis/drawdown page in the related links below first will speed up your understanding.
Why Divide by "Maximum Drawdown" of All Things?
There are various ways to measure risk. The Sharpe Ratio divides by how jagged the returns are (volatility). But what an investor really can't stand isn't the "upward jumps" but "the moment my account gets cut in half."
The Calmar Ratio takes that "most painful moment," the maximum drawdown, as its measure of risk. So it shows very intuitively that "to gain this much, in the worst case you had to endure this much."
Originally, this metric was made to evaluate the performance of hedge funds and commodity trading advisors (CTAs). The purpose was to not miss the "deep valley" hidden behind a big return.
The Origin of the Name and Its Creator
The Calmar Ratio was first introduced in October 1991 by American asset manager Terry W. Young in the trade journal 'Futures.'
The name 'Calmar' is a compound made from the initials of his company and newsletter name, 'CALifornia Managed Accounts Reports.' It's not a person's name or a difficult math term—just an abbreviation of a company name.
The original definition was "the average annual return of the most recent 36 months (3 years) ÷ the maximum drawdown of the most recent 36 months." Using a 3-year period was a balance point to capture enough of the market's ups and downs while not being swayed by performance too far in the past. For reference, this is a form that slightly changed the existing 'Sterling Ratio' from an annual to a monthly calculation.
How to Read the Number?
The higher the Calmar Ratio, the more it means an investment that "hurt less and earned well." The rough guidelines commonly used in practice are these.
① 3.0 or higher → very excellent (the annual return is more than 3 times the worst drawdown) ② 1.0 – 3.0 → good (the worst loss is roughly recouped with 1–3 years of return) ③ Below 1.0 → it takes more than a year just to fill the worst drawdown
However, these guidelines are just convention, not "absolute truth." Over a short period, the Calmar Ratio can look better than it really is simply because a large decline happened to not occur. So you must always check together over what period it was measured and whether that period included a real crisis (for example, a big crash).
Because the Calmar Ratio depends on exactly one "maximum drawdown," it is very sensitive to when and how that drawdown occurred. For example, the S&P 500 fell about -56% from October 2007 to March 2009 and took more than 5 years to recover its high, and depending on whether such a crisis is included in the measurement period, the same asset's Calmar score can change greatly.
Frequently Asked Questions
Q. What's the difference between the Calmar Ratio and the Sharpe Ratio?
Both measure "return relative to risk," but their definitions of risk differ. The Sharpe Ratio divides by the total volatility (jaggedness) of returns, while the Calmar Ratio divides by a single maximum drawdown, the largest fall from peak. Since what investors actually get scared and sell over is often a big decline, people say the Calmar Ratio shows "felt pain" more intuitively.
Q. Is a high Calmar Ratio unconditionally a good asset?
You shouldn't conclude that. If a big crash happened to not occur during the measurement period, the Calmar Ratio can come out better than it really is. Also, this metric is calculated from past data, so it doesn't guarantee future returns or future drawdowns. Use it only as one reference metric, and it's safer to look at multiple periods and multiple metrics together.
Q. What happens to the Calmar Ratio if the maximum drawdown is 0?
Theoretically you'd be dividing by 0, making it infinite, but in reality it's almost impossible for any risk asset to have a drawdown of exactly 0. If a period is so short that there's almost no drawdown, that score is more likely because it "hasn't yet experienced a crisis" than because it's "truly safe," so interpret it with caution.
📋 Results are based on historical data; past returns do not guarantee future returns.
📋 This service is provided for educational purposes to help you understand investing, not as investment advice.