Standard Sink Drain Size

This size is precisely the diameter of the pipe instead of the length.

Standard sink drain size.

The standard size and setting every state may have different code on plumbing and it may affect the required size of the bathroom sink pipe. However most of the bathroom sinks use 1 inch drain pipe. So even though there are different sizes of drains for your bathroom sink according to the international code council the standard is 1 inch. The drain strainer the bowl shaped piece inside the drain mouth matches this dimension.

While a bathroom sink s design and overall size may vary from one model to the next the drain holes are fairly standard 1 25 inches being a general standard with widths of 1 5 inches and 1 625.