Calculate risk-adjusted returns with the Sharpe ratio, Sortino ratio, and compare portfolios side by side. Understand how much return you earn per unit of risk.
Enter your portfolio's return, the risk-free rate, and standard deviation to calculate the Sharpe ratio and see how well your risk is being compensated.
The Sortino ratio is like the Sharpe ratio but only penalizes downside volatility — because upside volatility is actually good for investors.
Compare the Sharpe ratios of up to 3 portfolios side by side to find which offers the best risk-adjusted return.
This scatter plot shows historical risk-return profiles for common allocations. The dashed line represents the Capital Allocation Line (optimal risk-return tradeoff).
Historical Sharpe ratios (10-year) for popular ETFs and asset classes, assuming a risk-free rate of ~4.5%.
The Sharpe ratio is the most widely used measure of risk-adjusted return in finance. It tells you how much excess return you receive for the extra volatility you endure holding a riskier asset. In simple terms: it measures the "bang for your buck" of taking risk.
The ratio was developed by William F. Sharpe, a professor at Stanford University, who first introduced it in his 1966 paper as the "reward-to-variability ratio." Sharpe went on to win the Nobel Memorial Prize in Economic Sciences in 1990 for his contributions to the Capital Asset Pricing Model (CAPM) and the theory of price formation for financial assets.
The formula is elegantly simple: take your portfolio's return, subtract the risk-free rate (what you'd earn from Treasury bills with zero risk), and divide by the portfolio's standard deviation (a measure of volatility). The result tells you the units of return earned per unit of risk taken.
Raw returns can be misleading. A fund returning 20% sounds great — until you learn it had 40% volatility and nearly went to zero twice. Another fund returning 10% with just 8% volatility may actually be the superior investment. The Sharpe ratio captures this distinction by normalizing returns against the risk taken to achieve them.
This is crucial for portfolio construction: by comparing Sharpe ratios across investments, you can build portfolios that maximize return for a given level of risk — the fundamental insight of Modern Portfolio Theory.
Three popular risk-adjusted return metrics, each with a different perspective on risk.
| Feature | Sharpe Ratio | Sortino Ratio | Treynor Ratio |
|---|---|---|---|
| Formula | (Rp − Rf) / σp | (Rp − Rf) / σd | (Rp − Rf) / β |
| Risk Measure | Total volatility (std dev) | Downside deviation only | Beta (systematic risk) |
| Penalizes Upside? | Yes | No | No |
| Best For | General comparison | Asymmetric return profiles | Diversified portfolios |
| Developed By | William Sharpe (1966) | Frank Sortino (1980s) | Jack Treynor (1965) |
| Limitation | Treats all volatility equally | Requires downside data | Only captures market risk |
Understanding what different Sharpe ratio values mean in practice can help you evaluate investments more effectively. Here is a practical breakdown:
The portfolio is not adequately compensating for risk. You could likely achieve similar returns with less volatility, or earn more return for the same risk. Example: a speculative stock fund returning 8% with 20% std dev and 4.5% risk-free rate gives a Sharpe of 0.18.
Reasonable risk-adjusted performance, roughly in line with the broad stock market. The S&P 500 historically sits in this range. Example: a balanced fund returning 10% with 11% std dev gives a Sharpe of 0.50.
Strong risk-adjusted returns that outperform the market on a volatility-adjusted basis. Many top-performing hedge funds and managed strategies target this range. Example: a diversified portfolio returning 14% with 9.5% std dev gives a Sharpe of 1.0.
Exceptional risk-adjusted performance, rarely sustained over long periods. If you see a Sharpe above 3.0 over multi-year periods, scrutinize the data — it may indicate survivorship bias, overfitting, or unrealistic assumptions. Example: a trend-following fund returning 18% with 6.5% std dev gives a Sharpe of 2.08.
The Sharpe ratio measures risk-adjusted return by subtracting the risk-free rate from the portfolio return and dividing by the portfolio's standard deviation. The formula is: Sharpe Ratio = (Rp - Rf) / σp. A higher ratio indicates better compensation for risk taken. For example, if your portfolio returns 12%, the risk-free rate is 4.5%, and your standard deviation is 15%, the Sharpe ratio is (12 - 4.5) / 15 = 0.50.
A Sharpe ratio above 1.0 is generally considered good, above 2.0 is excellent, and above 3.0 is exceptional. The S&P 500 has historically delivered a Sharpe ratio of approximately 0.5 to 0.7 over long periods. Most professional fund managers consider consistently achieving a Sharpe ratio above 1.0 to be a strong achievement.
The Sharpe ratio uses total standard deviation (both upside and downside volatility) as its risk measure, while the Sortino ratio uses only downside deviation. This makes the Sortino ratio more suitable for investments with asymmetric returns, as it does not penalize upside volatility — which investors actually welcome.
William F. Sharpe, a Stanford professor, introduced the ratio in 1966 as the "reward-to-variability ratio." He won the Nobel Prize in Economics in 1990 for his work on the Capital Asset Pricing Model (CAPM). The measure was later renamed in his honor and remains the gold standard for risk-adjusted performance evaluation.
Yes, a negative Sharpe ratio means the portfolio underperformed the risk-free rate. You would have been better off holding Treasury bills. This can happen during bear markets or with poorly performing investments. When comparing two negative ratios, be cautious — the math becomes counterintuitive, and a "less negative" ratio does not always mean better performance.