EWMA Volatility Calculator Excel Template
EWMA Volatility Calculator Excel Template
Interactive Excel Financial Model
Download, customize, and integrate into your own analysis
What's Included
- Interactive financial model with live Excel formulas
- All formulas visible and fully editable
- Professional formatting with color-coded inputs & outputs
- Formula reference sheet with variable definitions
- Step-by-step instructions sheet
- Compatible with Microsoft Excel 2016 and later
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Price range: $0.00 through $20.00
EWMA and GARCH(1,1) volatility estimation Excel template with live formulas. Calculate daily and annualized volatility from returns data.
Online Calculator vs Excel Template
| Feature | Online | Excel |
|---|---|---|
| Instant use — no download | ✓ | — |
| Works offline | — | ✓ |
| Customize formulas & layout | — | ✓ |
| Save & share with colleagues | — | ✓ |
| Integrate into your own models | — | ✓ |
| Print-ready formatting | — | ✓ |
About This Template
Estimate daily volatility using the same methods used by professional risk managers. This EWMA Volatility Calculator Excel template implements both the Exponentially Weighted Moving Average (EWMA) and GARCH(1,1) models from Hull's "Options, Futures, and Other Derivatives" - the industry-standard approach popularized by JP Morgan's RiskMetrics.
What You Can Calculate
Enter your previous volatility estimate and latest return to instantly compute:
- EWMA Daily Volatility - Updated volatility using exponential weighting with adjustable lambda
- GARCH Daily Volatility - Mean-reverting volatility estimate with omega, alpha, and beta parameters
- Annualized Volatility - Both models scaled to annual terms using 252 trading days
- Half-Life - Days for a volatility shock to decay by 50%
- Long-Run Volatility (GARCH) - The equilibrium level volatility reverts to over time
- Alpha + Beta Sum - Stationarity check for GARCH model validity
Required Inputs
The template requires six inputs:
- Previous Volatility - Your prior daily volatility estimate (typically 1-3% for equities)
- Latest Return - Most recent period's percentage return
- Lambda - EWMA decay factor (0.94 is the RiskMetrics standard for daily data)
- Omega, Alpha, Beta - GARCH parameters (can be estimated from historical data)
Methodology
The EWMA model uses the recursive formula: sigma^2_n = lambda x sigma^2_{n-1} + (1-lambda) x r^2_{n-1}, giving more weight to recent observations. GARCH(1,1) adds mean reversion: sigma^2_n = omega + alpha x r^2_{n-1} + beta x sigma^2_{n-1}, where volatility reverts to the long-run level V_L = omega/(1-alpha-beta).
Assumptions & Limitations
- Single-asset volatility estimation (not multivariate)
- Uses simple percentage returns, not log returns
- Assumes returns are approximately mean-zero (standard for daily data)
- Annualization uses 252 trading days per year
Frequently Asked Questions
Copy the Calculator sheet and paste-values each day's result into a historical log. The template calculates one-period updates, so you can chain outputs by using today's EWMA/GARCH volatility as tomorrow's 'Previous Volatility' input. Many users build a time series by adding rows with dates and copying the formulas down.
This template performs one-step volatility updates using given parameters - it does not estimate omega/alpha/beta from historical returns. To calibrate parameters, you would need to run maximum likelihood estimation in a tool like Python, R, or specialized econometrics software, then enter the fitted values here.
The Excel template always displays both models for comparison, unlike the web calculator which has a toggle. This lets you see how the two estimates diverge under different market conditions and helps you decide which model suits your use case without switching views.
A fully interactive financial model with live Excel formulas, an Instructions sheet with usage guide, and a Formula Reference sheet with variable definitions and model assumptions. All formulas are visible and editable.
Microsoft Excel 2016 or later. The template uses standard Excel formulas only — no macros, VBA, or add-ins required.
Yes. All cells are fully editable. You can modify any formula, add your own calculations, change formatting, or integrate the model into your existing spreadsheets.
The online calculator runs in your browser for quick calculations. This Excel template gives you a portable, offline financial model you can customize, save, share with colleagues, and integrate into your own analysis.
This template is provided for educational and personal use. You may use it in your own professional analysis and presentations. Redistribution or resale of the template itself is not permitted.
You can re-download the latest version from your account or by requesting a new download link. Free downloads are limited to 5 per email address per month.
