Standard Space for Bathtubs

Traditional Bathtubs

• Even standard bathtubs have a range of sizes. According to "The Smart Approach to Bath Design" by Susan Maney Lovett, the smallest tubs are 30 inches wide and 60 inches long, but you can also find larger 36-by-72-inch bathtubs. To find the perfect fit for your body type, sit in the tub before you buy it, if possible. This will ensure you get the most comfortable option.

Whirlpool Bathtubs

• Whirlpool bathtubs shoot massaging jets of water from the sides of the tub. These are usually wider than traditional tubs. Sizes for these bathtubs start at 60-by-60 inches and increase from there. Whirlpool tubs are a good option for large bathrooms. Measure the depth of the whirlpool bathtub model to make sure that it is narrower than the bathroom door opening so you can get the unit inside.

Floor Space

• The amount of floor space required for a bathtub will be greater than the size of the tub. You must include open space on at least one side of the bathtub for a person to safely enter and exit. A person can enter a bathtub using either a parallel or a perpendicular approach. The method you use the most will help you to plan floor space. According to "Universal Design Handbook," by Wolfgang F. E. Preiser, et al., for a parallel approach to the bathtub, you must have at least 30 inches of depth along the entire length of a 60-inch-long bathtub. For a perpendicular approach, you need 48 inches of space on the side of a 60-inch bathtub.

Other Considerations

• Even if you have space for a large bathtub, your home's structure might not be able to support the fixture. According to "1001 Ideas for Bathrooms" by Jerri Farris, you must also look at the weight of a full tub. Deep soaking tubs, whirlpool bathtubs and those made of dense materials like stone or cast-iron put more pressure on the flooring from their weight. Check the support of your flooring and the weight of the full tub before making a selection at the store. To evenly distribute the weight of a large bathtub, install it perpendicular to the floor joists, as recommended in "The Smart Approach to Bath Design" by Susan Maney Lovett.