Calculator Inputs
Example Data Table
| Period | Return (%) | Comment |
|---|---|---|
| January | 2.4 | Strong opening month |
| February | -1.1 | Moderate pullback |
| March | 3.2 | Recovery and momentum |
| April | 0.8 | Stable advance |
| May | -0.5 | Short-lived weakness |
| June | 1.9 | Positive close |
| July | 2.7 | Strong performance |
| August | -1.8 | Higher volatility |
| September | 1.4 | Measured rebound |
| October | 0.9 | Balanced month |
| November | -0.7 | Minor drawdown |
| December | 2.1 | Year-end strength |
This sample lets you test the calculator quickly. Click “Load Example Data” to fill the form with these values.
Formula Used
Mean Return
Mean = (Sum of all returns) / n
Sample Standard Deviation
s = √[ Σ(Rᵢ − R̄)² / (n − 1) ]
Population Standard Deviation
σ = √[ Σ(Rᵢ − μ)² / n ]
Variance
Variance = (Standard Deviation)²
Annualized Volatility
Annualized Volatility = Periodic Standard Deviation × √(Periods Per Year)
Sharpe Ratio
Sharpe Ratio = (Mean Return − Target Return) / Standard Deviation
The calculator converts percent inputs to decimals before computation. Final display values are shown in percentage form for easier interpretation.
How to Use This Calculator
- Enter a portfolio or return series name for reporting clarity.
- Select whether your values are percentages or decimals.
- Choose sample or population deviation, depending on your dataset.
- Set periods per year to match monthly, weekly, daily, or custom returns.
- Enter any target or risk-free return per period, if needed.
- Paste return values into the input box using lines, commas, spaces, or semicolons.
- Click the calculate button to display results above the form.
- Download CSV for spreadsheets or PDF for sharing and documentation.
Frequently Asked Questions
1. What does standard deviation of returns measure?
It measures how far returns typically move from their average value. A higher standard deviation means returns are less stable and more volatile across the measured periods.
2. When should I use sample instead of population deviation?
Use sample deviation when your dataset is only part of a larger process, such as recent monthly returns. Use population deviation when your list contains the entire set you want analyzed.
3. Should I enter returns as percentages or decimals?
Choose the mode that matches your source data. Enter 2.5 for 2.5% in percent mode. Enter 0.025 for the same return in decimal mode.
4. What is annualized volatility?
Annualized volatility scales periodic standard deviation to a yearly basis. It helps compare return risk across datasets that use different time frequencies, such as monthly and daily returns.
5. Why is variance also shown?
Variance is the squared form of standard deviation. Analysts often use it in risk models, optimization work, and statistical comparisons before converting back to standard deviation.
6. What does downside deviation tell me?
Downside deviation measures harmful volatility only, based on returns below the selected target. It is useful when you care more about shortfalls than upside movement.
7. Can I use this for stocks, funds, or portfolios?
Yes. You can analyze any consistent return series, including stocks, mutual funds, ETFs, strategies, or model portfolios, as long as all returns use the same period length.
8. Why does the Sharpe ratio become undefined sometimes?
If standard deviation is zero, all returns are identical and the Sharpe ratio cannot divide by volatility. In that case, the result is mathematically undefined.