How do you calculate fully diluted shares?

To calculate fully diluted shares, we need to add the basic number of shares (found on the cover of a company’s most recent 10Q or 10K) and the dilutive effect of employee stock options.  To calculate the dilutive effect of options we typically use the Treasury Stock Method.  The options information can be found in the company’s latest 10K.  Note that if the company has other potentially dilutive securities (e.g. convertible preferred stock or convertible debt) we may need to account for those as well in our fully diluted share count.