A world-wide-web based size information system and method for providing any living thing with an accurate size information profile to facilitate the purchase of appropriately fitted products to help and support that living thing's needs. The inventive system includes; a size recording process, a database for online or offline input of the sizes, the ability to view and share the size information, grouping and sub-grouping of individual user information on demand, grouping and sub-grouping of system users on demand, comparison of system user sizes on demand, comparison of user sizes to an article on demand, cross reference of international sizes for a user, and the creation of an international size reference by country.