Standard Sink Drain Size

However most of the bathroom sinks use 1 inch drain pipe.

Standard sink drain size.

This is the measurement across the center of the drain from one side to another. 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. Even if you get a new faucet for the bathroom sink you need to buy a drain of these sizes. So even though there are different sizes of drains for your bathroom sink according to the international code council the standard is 1 inch.

According to signature hardware a standard kitchen drain is 3 1 2 inches in diameter.