How to find out if my site have a duplicated pages ?

duplicated pages can harm your search engine position.

you will need to look for duplicated pages sometimes by tools like CopyScape .

copyscape.com look at your page and check for duplicated pages all over google index.

google used to view all the duplicated pages well you write site:www.your-url.com

but not any more.

so how to calculate duplicated pages ?

just go to google and write:

site:www.url.com/&

then write:

site:www.url.com/*

take the first result (number if index pages) and decrees the second result (number of index pages).

the result will tell you how many page in this site are duplicated.