Two investments can deliver the same average return and still be very different propositions. The Sharpe ratio answers the question that matters to a rational investor: how much return did I get for the risk I actually took? It compares the return above the safe rate to the volatility of the returns and collapses both into a single number you can compare across funds and portfolios.
What Is the Sharpe Ratio Calculator?
The Sharpe ratio measures how much return an investment produced for each unit of risk. It was named after William Sharpe, who won the Nobel Prize in Economics for work on this kind of risk-adjusted performance measure.
Put simply, if a fund returns 12 percent while cash returns 4 percent, and its returns swing around by 15 percent year to year, the fund earned 8 percentage points above the safe rate for taking on 15 points of volatility. That ratio of 0.53 is the Sharpe score.
How the Sharpe Ratio Formula Works
Sharpe ratio = (Return of the investment − Risk-free rate) ÷ Standard deviation of returns
Both the return and the risk-free rate should be annualised and expressed as decimals so the units cancel. The standard deviation is the volatility of the investment’s returns, which is why the calculator asks for it directly rather than trying to infer it.
How to Read a Sharpe Ratio
The classic benchmarks are below 1 for weak, 1 to 2 for acceptable, 2 to 3 for strong and above 3 for exceptional. A ratio of 0 means the investment earned no more than cash while still carrying risk, and a negative ratio means it returned less than the safe rate while still being volatile.
The calculator adds two practical reference points. The risk-free rate you would need for a Sharpe of 1 shows whether the current return could survive a rise in cash yields, and the volatility you could tolerate at a Sharpe of 1 shows how much more volatility the investment could take before its score dropped below the acceptable line.
Limitations of the Sharpe Ratio
The ratio treats all volatility as bad, including volatility you would be happy to accept because you are trying to save for a house in two years. For long-term investors who rebalance and hold, smoothing that volatility often improves the outcome, and the Sharpe ratio gives no credit for it.
It also compares against a single risk-free rate, so it can mislead during periods when long-term government bonds yield far more than short-term cash. And because it uses the whole distribution in a single number, two funds with identical Sharpe ratios can behave very differently in a crash.
Frequently Asked Questions
What is a good Sharpe ratio?
Below 1 is generally considered weak, 1 to 2 acceptable, 2 to 3 strong and above 3 excellent. The benchmark you should use depends on the asset class, because a diversified equity fund and a corporate bond fund are not competing on the same risk.
How do I find the volatility of an investment?
Volatility is the standard deviation of the investment’s returns, usually calculated from a period of monthly or annual returns. Most fund fact sheets publish it, and portfolio tools such as a tracking error figure give you a closely related number.
What risk-free rate should I use?
Use the yield on a government bill or short-term bond in the currency of the investment and matched to your holding period. The calculator uses the same figure for both the Sharpe calculation and the reference points, so consistency matters more than the exact source.
Can the Sharpe ratio be negative?
Yes. A negative Sharpe ratio means the investment returned less than the risk-free rate while still carrying volatility, so the risk was not rewarded at all. A ratio of zero means the return exactly matched the safe rate.
How does the Sharpe ratio compare to the Sortino ratio?
The Sortino ratio uses downside volatility only, ignoring the upside swings that investors actually enjoy. It gives a higher score for portfolios that rise sharply in some years, which is why some investors prefer it for evaluating a fund they plan to hold long term.