The recommended height for hanging a towel bar is 48 inches from the floor. The average height of most Americans and the average length of bath towels are combined to arrive at this figure.
At 48 inches from the floor, most towels and bath sheets hang on a towel bar without touching the floor. However, there is no one proper height for hanging a towel bar. Increase or decrease this height as necessary to take into account very tall or short members of a household, and consider placement. Hang towel bars close enough to the sink and bath so that towels are within reach when needed.