Sharpe Ratio Calculator
Calculate the Sharpe ratio to measure how much excess return your portfolio earns per unit of risk. Investors use it to compare funds, strategies, or portfolios on a risk-adjusted basis.
About this calculator
The Sharpe ratio, developed by Nobel laureate William F. Sharpe, quantifies the reward an investor receives for taking on additional risk beyond a risk-free asset. The formula is: Sharpe Ratio = (portfolioReturn − riskFreeRate) / portfolioVolatility. The numerator, called the excess return or risk premium, is the return above what could be earned with zero risk (e.g., a Treasury bill). The denominator is the portfolio's standard deviation of returns, representing total volatility. A higher Sharpe ratio indicates better risk-adjusted performance. As a rule of thumb, a ratio above 1.0 is considered acceptable, above 2.0 is good, and above 3.0 is excellent. Negative Sharpe ratios indicate the portfolio underperformed the risk-free rate. The metric is most meaningful when comparing two portfolios with similar investment universes over the same time frame.
How to use
Suppose your portfolio has an annual return of 12%, the risk-free rate is 4%, and the portfolio's annual standard deviation is 10%. First, calculate the excess return: 12% − 4% = 8%. Then divide by volatility: Sharpe Ratio = 8% / 10% = 0.80. This means the portfolio earns 0.80 units of excess return for every unit of risk taken. If a competing fund returns 15% with a standard deviation of 20%, its Sharpe ratio is (15−4)/20 = 0.55 — lower than 0.80, so your portfolio is delivering better risk-adjusted performance despite the lower absolute return.
Frequently asked questions
What is a good Sharpe ratio for an investment portfolio?
A Sharpe ratio above 1.0 is generally considered acceptable for most investment portfolios. Ratios between 1.0 and 2.0 are regarded as good, while anything above 2.0 is considered very strong and above 3.0 is exceptional. These benchmarks can vary by asset class — hedge funds and equity strategies are often held to higher standards than bond-heavy portfolios. It is most useful to compare the Sharpe ratio of a fund against its peers or a relevant benchmark rather than applying absolute thresholds in isolation.
How does the risk-free rate affect the Sharpe ratio calculation?
The risk-free rate serves as the baseline return an investor can earn with essentially no risk, typically represented by short-term government securities like U.S. Treasury bills. A higher risk-free rate reduces the excess return in the numerator, lowering the Sharpe ratio even if the portfolio's performance is unchanged. This is why Sharpe ratios computed during high-interest-rate environments may look less impressive than those from low-rate periods. When comparing ratios across different time periods, always verify that the same risk-free rate benchmark was used to ensure a fair comparison.
What is the difference between the Sharpe ratio and the Sortino ratio for measuring risk-adjusted returns?
The Sharpe ratio uses total standard deviation (both upside and downside volatility) as its risk measure, treating positive and negative deviations equally. The Sortino ratio is a modification that only penalizes downside volatility — the standard deviation of negative returns — making it more relevant for investors who are primarily concerned with losses rather than gains. As a result, portfolios with large upside swings can look artificially risky under the Sharpe framework but much better under the Sortino framework. Both metrics are valuable; the Sharpe ratio is more universally recognized, while the Sortino ratio provides a more nuanced view of downside risk.