How do you work out page numbers?

The usual way for a book to be paginated is for the odd numbers to be on the right hand pages and the even page numbers on the left page. If the book or booklet is made up ‘collate, fold and stitch, the number of pages needs to be divisible by four. When we ask “How many pages is it?” we mean if you were to put page numbers on the item, what would be the last page number? For example, if you have three sheets of A4 folded down to A5, this is a 12 page A5 booklet. Your book/booklet will either be ‘self cover’ (same type of paper on every page) or plus cover.