Does anybody know a web in which you can calculate the value of an option??

Answer 1

I guess this will help you
http://www.optionspricevaluation.com

Answer 2

The truth is, no one knows how to value options. Economics has been trying to model this for a very long time, and nothing we do actually works. So, I will give you this rule of thumb. If you are willing to invest the money to buy the underlying stock at that price anyway, it is a good price. If not, it is a bad price. Black-Scholes does not work and never has and cannot. It can even be proven it cannot work. However, at this moment we lack a better alternative model. You can find one at the CBOE, or www.cboe.com, but ignore it. It doesn't work.