I have conflicting info about how long a page title can be before it is truncated on a SERP. To my understanding I thought it was 70 characters, but recently I have heard that it is 65?
I've been told and read in books that 65 is the ideal length including spaces the reason being is that search engines will truncate the page title to this length in the browers. I believe Google truncates the page title to the nearest complete word though.
Hope this helps.
The title is being count by characters and limited with characters not with words. That is why you should really care on how many characters you have rather than how many words because it depends on you on how descriptive your title would be in just a specific number of characters and how it would benefit your site.