Sharpe Ratio Calculator Using Daily Returns
Analyze investment risk-adjusted performance with our professional Sharpe Ratio calculator
Sharpe Ratio Calculator
Enter daily returns to calculate the Sharpe Ratio for your investment portfolio.
Typical daily risk-free rate (e.g., Treasury bill yield divided by 365)
Enter daily percentage returns separated by commas
Sharpe Ratio Results
Daily Returns Visualization
Returns Analysis Table
| Metric | Value | Description |
|---|---|---|
| Average Daily Return | – | Mean of all daily returns |
| Risk-Free Rate | – | Daily risk-free interest rate |
| Excess Return | – | Average return minus risk-free rate |
| Standard Deviation | – | Volatility of daily returns |
| Sharpe Ratio | – | Return per unit of risk |
What is Sharpe Ratio?
The Sharpe Ratio is a measure of risk-adjusted return developed by Nobel laureate William F. Sharpe. It helps investors understand the relationship between risk and return for an investment or portfolio. The Sharpe Ratio calculates the excess return per unit of deviation in an investment, providing insight into how well the return of an asset compensates the investor for the risk taken.
Investors and portfolio managers use the Sharpe Ratio to evaluate the performance of investments, compare different portfolios, and make informed decisions about risk allocation. A higher Sharpe Ratio indicates better risk-adjusted performance, meaning the investment provides more return for each unit of risk taken.
Common misconceptions about the Sharpe Ratio include thinking it measures absolute performance rather than relative performance, assuming it works equally well for all types of investments, and believing that a high Sharpe Ratio always indicates a good investment regardless of other factors.
Sharpe Ratio Formula and Mathematical Explanation
The Sharpe Ratio formula using daily returns is calculated as follows:
Sharpe Ratio = (Average Daily Return – Risk-Free Rate) / Standard Deviation of Daily Returns
This formula measures the excess return earned above the risk-free rate per unit of volatility or total risk. The numerator represents the risk premium earned by investing in the risky asset, while the denominator represents the risk taken to earn that premium.
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Expected Return | Average return of the investment | Percentage per period | -5% to +5% daily |
| Risk-Free Rate | Return with zero risk | Percentage per period | 0% to 0.1% daily |
| Standard Deviation | Measure of volatility | Percentage | 0.5% to 3% daily |
| Sharpe Ratio | Risk-adjusted return | Dimensionless | Negative to +2.0+ |
The Sharpe Ratio can be annualized by multiplying by the square root of the number of periods in a year (e.g., √252 for daily returns).
Practical Examples (Real-World Use Cases)
Example 1: Stock Portfolio Analysis
Consider a portfolio with daily returns of 0.5%, -0.2%, 1.1%, -0.3%, 0.8%, 0.2%, -0.1%, 0.9%, 0.4%, -0.5%. The average daily return is 0.28%, with a standard deviation of 0.54%. With a daily risk-free rate of 0.02%, the Sharpe Ratio would be (0.28% – 0.02%) / 0.54% = 0.48. This indicates the portfolio generates 0.48 units of excess return per unit of risk.
Example 2: Mutual Fund Comparison
When comparing two mutual funds, Fund A has an average daily return of 0.35% with 0.6% standard deviation, while Fund B has 0.28% average return with 0.4% standard deviation. With a risk-free rate of 0.02%, Fund A’s Sharpe Ratio is (0.35% – 0.02%) / 0.6% = 0.55, and Fund B’s is (0.28% – 0.02%) / 0.4% = 0.65. Despite lower absolute returns, Fund B offers better risk-adjusted performance.
How to Use This Sharpe Ratio Calculator
Using our Sharpe Ratio calculator is straightforward and requires just two inputs:
- Enter the daily risk-free rate (typically the Treasury bill yield divided by 365)
- Input your daily returns data, separated by commas in the text area
- Click “Calculate Sharpe Ratio” to see immediate results
- Review the primary Sharpe Ratio result along with supporting metrics
- Analyze the visualization chart showing your daily returns pattern
- Use the results table for detailed performance analysis
To interpret results, remember that a Sharpe Ratio above 1.0 is generally considered good, above 2.0 is very good, and above 3.0 is excellent. Negative ratios indicate poor risk-adjusted performance where returns don’t compensate for the risk taken.
Key Factors That Affect Sharpe Ratio Results
1. Volatility of Returns
Higher volatility increases the denominator of the Sharpe Ratio, reducing the overall value. Investments with more stable returns typically have higher Sharpe Ratios.
2. Average Return Level
The numerator depends on the difference between average return and risk-free rate. Higher average returns, all else equal, increase the Sharpe Ratio.
3. Risk-Free Rate Environment
Changes in risk-free rates affect the excess return calculation. Rising interest rates can improve Sharpe Ratios for positive-return investments.
4. Time Period Selection
The length of the measurement period affects both average return and standard deviation calculations, impacting the final ratio.
5. Market Conditions
Bull markets may inflate Sharpe Ratios due to higher returns, while bear markets may deflate them due to negative returns and increased volatility.
6. Investment Strategy
Different strategies (value vs. growth, momentum vs. mean reversion) will produce different risk-return profiles affecting the Sharpe Ratio.
7. Asset Allocation
The mix of assets in a portfolio affects both returns and risk, directly impacting the Sharpe Ratio through diversification benefits.
8. Frequency of Rebalancing
How often a portfolio is rebalanced can affect return patterns and risk levels, influencing the Sharpe Ratio calculation.
Frequently Asked Questions (FAQ)
A negative Sharpe Ratio indicates that the investment’s return is less than the risk-free rate, meaning the investor is taking on risk without adequate compensation. This suggests poor risk-adjusted performance.
Generally yes, but extremely high Sharpe Ratios may indicate survivorship bias, look-ahead bias, or insufficient data. Very high ratios might not be sustainable over longer periods.
To annualize the Sharpe Ratio calculated from daily returns, multiply by the square root of 252 (the typical number of trading days in a year). For monthly returns, multiply by the square root of 12.
The Sharpe Ratio works best for investments with normally distributed returns. It may be less appropriate for investments with asymmetric return distributions or those that employ leverage.
A Sharpe Ratio above 1.0 is generally considered good, above 2.0 is very good, and above 3.0 is excellent. Ratios below 0.5 are considered suboptimal.
The risk-free rate serves as the baseline for measuring excess return. Higher risk-free rates reduce the excess return component, potentially lowering the Sharpe Ratio for the same investment.
The Sharpe Ratio helps portfolio managers optimize risk-adjusted returns by identifying which investments provide the most return per unit of risk, enabling better asset allocation decisions.
At least 30 data points are recommended for statistical significance, though more data points (e.g., 60+ days) provide more reliable estimates of the true Sharpe Ratio.
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