Great advice! And this should be done before opening your position.
A four leg position simulator:
http://www.888optionsnet.com/invest...onSimulator.asp
An ok options calculator:
http://www.888options.com/resources/options_calc.jsp
An options sensitivities simulator:
http://www.ftsweb.com/newfts/opsens.htm
Another option calculator:
http://www.ftsweb.com/options/opbarr.htm
A 20 leg expiration calculator:
http://www.optionstrategist.com/fre...tion/index.html
Quote from optioncoach:
Plug the legs of the straddle in an option calculator and study the GREEK movements of each. ...