One inch of skin showing around the stomach is the limit to what I think should be worn in public, and that inch should never include your belly button. (tailoredandtrue.com)
You do not want to show more than a few inches of skin at the top's shortest point, with one inch or less around the rest of the top being preferable. (fortheloveofbubbly.com)
Meanwhile, my husband came out of the woods, slapping his neck, every exposed inch of skin covered with rising red welts. (bookpage.com)