What is minimum bedroom size by code?

The ICC 2006 International Residential Code states: no habitable space may be less than 70 square feet. A bedroom is considered a habitable space. Some building officials do not concider the closet part of that space and some do. Best to ask your building department. Although this is a code reference, it is not a code interpretation. Codes vary from area to area and should always be verified with your local authority. Some areas do not use the IRC and some amend the IRC. Your local building official can help you much more than I can. Hope this helps! Terry, CBO