How to calculate size of INT(x) field

Hi all, Sorry for such a newbie question! But I have been digging through the O'Reilly MySQL book + MySQL Cookbook and cannot find an answer to what I think is a very simple question: When creating an unsigned INT field, how does the value in brackets (if given) limit the size of the field? I.e. what is the difference in possible maximum values held between an INT(10) and an INT(4)? I know MySQL will create an INT(10) as standard but I'm not sure I need it to be able to hold a number that high. -- Best regards, Richard Davey http://www.phpcommunity.org/wiki/296.html