Most big box stores offer a diverse selection of bathtub sizes and styles, ranging from 54 to 72 inches long, 30 to 48 inches wide, and 14 to 25 inches high. There are no standard sizes for bathtubs because manufacturers’ specifications differ slightly in length, width and height.
The most popular styles of bathtubs are alcove, free standing and corner tubs. The alcove bathtub is the most common style. It fits between three walls and takes up the least amount of space. Its usual length is 60 inches, but some are as short as 53 inches or as long as 72 inches. Free-standing tubs, such as claw foot and slipper tubs, are usually oval shaped and have exposed plumbing. Corner tubs take up the most space, and are either five-sided, or have two straight sides with a curved front.
The size of a bathtub is its outside measurement only and is not indicative of the size of the inside or how much water it holds. Inside dimensions vary significantly depending on bathtub shape, style and construction material. A typical 60-inch-long bathtub can hold from 58 to 75 gallons of water, whereas a 72-inch-long bathtub can hold up to 82 gallons.