A bathroom sink is used for basic hand washing, shaving and cleaning, all of which require a certain amount of space. The size of the bathroom sink corresponds to its usage. There is no set standard size for bathroom sinks and countertops. However, some sizes are fairly common and certain parts of the sink are standardized.
Typical Sink Bowl Diameters
There is no set standard bowl size for bathroom sinks, according to Lowe's. However, when you buy a sink for a countertop, you will find most fall within a certain size range. Most round sinks are 16 to 20 inches in diameter, whereas most rectangular bathroom sinks are 19 to 24 inches wide and 16 to 23 inches front to back.
This width varies due to the shape of the bowl as well. Oval bowls have a wider diameter on one side, and the largest overall dimension is used to determine width in an oval bowl. When purchasing an oval bowl, consider this if bowl size and volume are important to you.
Typical Bathroom Sink Depth
The typical sink bowl basin depth is 5 to 8 inches. The shape and size of the bowl affects the depth measurement in most cases. Some large bowls have a shallower depth, but due to their size still hold more water and have more room.
Bowl depth is important to consider because it affects drain installation. The sink drain installs under the sink, so enough clearance for the drain is required. A really deep sink bowl may not have enough clearance for the drain.
Size of Vanity Tops
Vanity tops combine a bathroom sink bowl and the counter in one piece. The vanity is usually made from ceramic, porcelain or stone. A vanity top has no standard size. The sink bowl and countertop vary in size.
Typical vanity cabinet widths are 24, 30, 36, 48 and 60 inches wide. The vanity countertop should be an inch wider and an inch deeper than the cabinet. A typical vanity depth is 17 to 24 inches. This is important, because standard building codes require at least 18 inches from the cabinet edge to the center of the toilet.
The size of the sink bowl in a vanity depends on the vanity size and the number of sink bowls in the vanity. Some vanity tops have two or even three sink bowls.
Countertop Height and Dimensions
While countertop sizes vary greatly, and have a big impact on sink bowl size, the height of the countertop is more standardized. Most bathroom countertops are 31 inches high, a standard for kitchen countertops as well. However, bathroom countertops range from 30 to 36 inches.
This height allows for storage inside the counter and it places the sink bowl at an accessible height for the average adult. While the size of the countertop has more affect on the size of the sink bowl, the height affects the depth of the sink bowl. You can adjust the mounting of your vanity for small adjustments in height.
Steve Smith has published articles on a wide range of topics including cars, travel, lifestyle, business, golf, weddings and careers. His articles, features and news stories have appeared in newspapers, consumer magazines and on various websites. Smith holds a Bachelor of Arts in English and journalism from University of New Hampshire Durham.