Sometimes, a bathroom is too small to fit a regularly sized bathtub in, but there are small bathtubs available for these tiny places. Small bathtub designs are influenced by the common Japanese bathtubs. Japanese tubs are much smaller than Western tubs, causing the person bathing to be more vertical than horizontal. Because western bathtub users generally prefer to soak deeply in the water, the idea of sitting in a small bathtub may seem like it wouldn't be warm or enjoyable, but this isn't true. Small tub designs today are just as comfortable and as easy to bathe in as large tub designs in bigger bathrooms.
A bathroom that is not very wide won't allow for a bathtub that is long enough to lie in, but a small bathtub can run very deep, sometimes with a seat inside, to allow for an in-depth bathe even though the person would only be sitting down. These deep tubs don't have to be sunk into the floor to fit into the bathroom either. It's possible with modern technology to raise the bathtub onto a pedestal before sinking it into the floor. So in the end, the bottom of the bathtub is on the original floor, but because the pedestal ledges cover the bottom of the bathtub, it doesn't look like the small bathtub is a giant hole.
Not only are there bathtubs that are smaller than the typical five feet, but there are tubs known as walk-in tubs. These tubs are very deep, so the only way one can enter them is by opening a door and walking into it. The disadvantage of this kind of bathtub is that you must be in the tub before you fill it with water and after you drain the water.
Fiberglass is a modern material commonly used to make bathtubs, and because it's so soft, it can be molded into virtually any shape necessary. Small tubs don't have to be rectangular, but they can be triangular, rounded, or trapezoid-shaped, depending on how the bathtub will fit into that little bathroom corner.