What Is The Rough-In Height For Sink Drains? - Upgraded Home A standard sink drain will be 24-28 inches from the floor. This means the rough-in height for a sink drain will need to be about 18-20 inches from the floor. This way, there's enough room for the P-trap and hot and cold water lines to fit into place. The rough-in height will vary based on the height of your counter and depth of your sink.