Sortino Ratio Calculator
Enter your average portfolio return, minimum acceptable return (MAR), and either the downside deviation directly or a set of historical period returns. The calculator gives you the Sortino ratio, excess return, and a side-by-side comparison with the Sharpe ratio so you can see exactly how much of your volatility penalty comes from downside moves only.
What is the Sortino ratio?
The Sortino ratio is a risk-adjusted performance metric developed by Frank Sortino in the early 1990s. It measures how much excess return a portfolio earns relative to the downside risk it accepts. Unlike the Sharpe ratio, which penalizes all volatility equally, the Sortino ratio only counts volatility below a target return (the minimum acceptable return, or MAR) as harmful. This distinction matters because investors generally do not object to upside surprises - the only risk that hurts is falling short of a target.
How to calculate the Sortino ratio
The formula is: Sortino Ratio = (Rp - MAR) / DR, where Rp is the average portfolio return, MAR is the minimum acceptable return (often the risk-free rate), and DR is the downside deviation. Downside deviation is computed in three steps: (1) for each period, subtract the MAR from the return and keep only the negative differences; (2) square each negative difference; (3) average all the squared differences across ALL periods (not just bad ones), then take the square root. Dividing by total periods rather than only bad periods prevents the metric from artificially inflating when most periods are good. If your period returns are sub-annual (monthly, weekly, daily), annualize the ratio by multiplying by the square root of the number of periods per year.
Sortino ratio vs. Sharpe ratio
The Sharpe ratio divides excess return by total standard deviation, treating upside and downside swings identically. For strategies that generate a lot of positive skewness - trend following, covered calls, or momentum - the Sharpe ratio understates quality because the good volatility inflates the denominator. The Sortino ratio avoids this by keeping only downside deviation in the denominator. As a result, a portfolio with a Sortino ratio noticeably higher than its Sharpe ratio is exhibiting favorable asymmetry: its volatility is weighted toward gains, not losses. Conversely, if the Sharpe is higher than the Sortino, large downside swings are disproportionate.
Interpreting and using the Sortino ratio
A value above 2 is widely considered good, and above 3 is excellent. Below 1 signals that each unit of downside risk is not being compensated by at least one unit of excess return, which most professional allocators find unattractive. A negative ratio means the strategy is delivering an average return below the MAR, which is hard to justify regardless of risk level. The ratio is most useful for ranking strategies within an asset class or comparing a fund against its stated benchmark, not for comparing across very different asset classes where risk levels are incomparable.
Sortino ratio interpretation guide
| Sortino Ratio | Assessment | What it signals |
|---|---|---|
| Below 0 | Unacceptable | Average return is below the MAR - downside risk is not compensated at all |
| 0 to 1 | Weak | Some excess return but each unit of downside risk is not fully rewarded |
| 1 to 2 | Acceptable | Reasonable risk-adjusted performance for most diversified portfolios |
| 2 to 3 | Good | Strong downside risk management - typical of top-quartile managers |
| Above 3 | Excellent | Exceptional - often seen in low-volatility or trend-following strategies |
General benchmarks used by portfolio managers. A "good" value depends on asset class and strategy style.
Frequently asked questions
What is a good Sortino ratio?
Most portfolio managers consider a Sortino ratio above 2 to be good and above 3 to be excellent. A ratio between 1 and 2 is acceptable for many diversified portfolios. Anything below 1 suggests the excess return is insufficient to compensate for the downside risk taken, and a negative ratio means the strategy is earning less than the minimum acceptable return on average.
How is downside deviation different from standard deviation?
Standard deviation measures the spread of ALL returns - both gains and losses - around the mean. Downside deviation measures only the deviation of returns that fall below the minimum acceptable return (MAR). Returns above the MAR are counted as zero deviation. The denominator in the downside deviation formula is the total number of periods (not just the bad ones), so a strategy with few bad periods will have a lower downside deviation than its standard deviation, resulting in a higher Sortino ratio than Sharpe ratio.
What should I use as the minimum acceptable return (MAR)?
The most common choice is the risk-free rate - typically the yield on short-dated government bonds such as 3-month US Treasury bills. Some investors use 0% (any loss is unacceptable), a hurdle rate (the cost of capital), or a benchmark index return. The choice affects both the excess return in the numerator and which periods count as downside in the denominator, so keep your MAR consistent when comparing strategies over time.
How do I annualize the Sortino ratio from monthly returns?
Multiply the per-period ratio by the square root of the number of periods per year. For monthly returns, multiply by sqrt(12) - about 3.46. For weekly returns, multiply by sqrt(52) - about 7.21. For daily returns (trading days), multiply by sqrt(252) - about 15.87. This calculator handles annualization automatically when you select a frequency in series mode.
Why is the Sortino ratio better than the Sharpe ratio for some strategies?
The Sharpe ratio penalizes upside volatility the same as downside volatility. For strategies with positively skewed returns - where large gains occur more frequently than large losses - the Sharpe ratio understates quality because the good swings inflate the denominator. The Sortino ratio ignores upside deviation, so it rewards strategies that deliver occasional large gains while keeping losses tight. This makes it more appropriate for options strategies, trend following, and any approach that deliberately cuts losses quickly.
Can the Sortino ratio be negative?
Yes. A negative Sortino ratio occurs when the average portfolio return falls below the minimum acceptable return (MAR). In that case the numerator (excess return) is negative, which makes the ratio negative regardless of the downside deviation. A negative ratio is generally a warning sign: the strategy is not even achieving the baseline target on average.