How to chart a Calmar ratio

The Calmar ratio divides a compound annual return by the deepest drawdown suffered over the same period, which answers a blunt question: how much annual return did this strategy pay per unit of its worst loss. Charted over time it becomes a rolling line, and that line looks unlike any other risk-adjusted ratio. It sits flat for long stretches and then steps, sharply. The shape is not noise. It falls directly out of a denominator that is one event rather than a spread, and reading it correctly starts with understanding why.

What the ratio actually is

Calmar equals CAGR divided by the absolute value of maximum drawdown. CAGR is the constant annual rate that reproduces an observed total return, computed as (1 + total return) raised to the power of 1 over the number of years, minus 1. Maximum drawdown is the largest peak-to-trough decline in the equity curve, found by tracking the running maximum and recording the deepest shortfall below it. Terry Young published the ratio in the trade journal Futures in 1991, and the name is an acronym of his newsletter, California Managed Accounts Reports. His definition was specific in a way most write-ups skip: the average annual return over the last 36 months, divided by the maximum drawdown over those same 36 months, recalculated monthly.

Calmar is not the MAR ratio

A competing newsletter, Managed Account Reports, had already popularized a similar measure: compound annual return since inception over maximum drawdown since inception. That is the MAR ratio, and the two names get used as if they were interchangeable. They are not. Calmar runs on a trailing 36-month window; MAR runs from day one. A fund with a clean recent record and one catastrophic year a decade ago will show a healthy Calmar and a poor MAR, and both numbers are honest. Whichever you publish, put the window in the caption.

Both halves must cover the same window

The most common error in a homemade Calmar is a mismatched window: an annualized return since inception paired with the worst drawdown of the last twelve months, or three years of return over a ten-year drawdown. The ratio then measures nothing coherent, and the mismatch is completely invisible in the finished chart. Fix the window once, apply it to both halves, and state it. If you are plotting Calmar as a rolling series, that means the numerator and the denominator slide together over identical bars.

Why the line moves in steps

A rolling Sharpe or Sortino moves continuously because its denominator is a dispersion statistic that every new observation nudges. Calmar's denominator is a single number: the worst drawdown inside the window. Until the strategy sets a new low relative to its running peak, that number does not move at all, so the line drifts only with the numerator. When a deeper drawdown finally arrives, the denominator jumps and the line steps down hard. A rolling window adds a second kind of step: as the window slides forward, an old drawdown eventually falls out of the trailing 36 months, the denominator shrinks, and the line steps up without the strategy having done anything. Both steps are events worth annotating rather than artifacts worth smoothing.

The sign trap

Drawdown is negative by convention and should be displayed as -20 percent, not 20 percent. The Calmar formula wants its absolute value. Miss that and every ratio comes out negative, which reads as a losing strategy and is nothing but a sign bug. If your drawdown function returns a magnitude instead, name the variable so the next person can see which convention they are holding.

A worked example

Take a fund that compounds 50 percent over three years. Its CAGR is 1.5 raised to the power of one third, minus 1, which is 14.47 percent. Over those same 36 months its deepest peak-to-trough decline was 20 percent, so Calmar is 0.1447 divided by 0.20, or 0.72. Now make the window mistake: keep the three-year return but pair it with the worst drawdown of the last twelve months only, say 8 percent. The ratio becomes 0.1447 divided by 0.08, or 1.81. Same fund, same returns, a number two and a half times better, produced entirely by an inconsistent window. These figures are an illustration built from the formulas rather than a measurement of a live fund; run it on your own equity curve and the two versions will diverge the same way.

How to read the level

A Calmar above 1.0 is commonly treated as strong, and much higher figures get quoted for good managed-futures records, but treat those as industry conventions rather than statistical thresholds. There is a mechanical reason to be careful with them: Calmar tends to fall as the window lengthens, because a longer history gives the drawdown more chances to set a record while the CAGR stays roughly where it was. Comparing two funds is only meaningful at equal windows, which is precisely what the 36-month convention exists to enforce. Note also that CAGR is not meaningful under a year, so a six-month Calmar is not a number worth plotting.

Calmar is best read directly above the chart it depends on. Its denominator is the same quantity you plot in an underwater drawdown curve, so stacking the two makes each step in the ratio explainable by a visible trough, and the rolling Sharpe and rolling Sortino lines show whether the risk being penalized is dispersion or one bad run. Quadesto takes an equity curve and a window and plots the three together with the window and drawdown convention named in the caption. [QUADESTO-EMBED: rolling 36-month Calmar ratio with the underwater drawdown curve stacked below, shared time axis, step events annotated]. The free tier embeds it live with a Made with Quadesto credit; Pro at 149 pounds a month removes the attribution and adds branded themes.