voltality index

[sfunds]

I have eod data for last five years of NSE scripts (Indian)

I want to calculate the voltality index.
can someone suggest the method

thanks

 

[auspiv]

http://lmgtfy.com/?q=calculate+volatility

 

[matador04]

search for a VIX white paper, they show the details of the calculation over a rolling 30 day period