http://www.optionsprofitcalculator.com/ http://www.optionsprofitcalculator.com/ seems to be kind of popular, but it's not the most intuitive to use. I think of

http://www.optionsprofitcalculator.com/ http://www.optionsprofitcalculator.com/ seems to be kind of popular, but it's not the most intuitive to use. I think of this as something that many brokerages offer...