Standard Bathroom Sink Drain Pipe Size

The standard bathroom sink drain pipe size is 1 1/2 inches in diameter. This is the size of the pipe that connects the sink drain to the P-trap. The P-trap is the U-shaped pipe that prevents sewer gases from entering the bathroom. The 1 1/2-inch pipe is the most common size for bathroom sinks, but some sinks may have a 2-inch drain pipe.

If you are replacing a bathroom sink, it is important to make sure that the new sink has the same size drain pipe as the old sink. If the new sink has a different size drain pipe, you will need to purchase a new P-trap that is the correct size for the new sink.

In addition to the 1 1/2-inch drain pipe, there are also several other standard sizes for bathroom sink drain pipes. These sizes include:

1 1/4 inches
1 3/8 inches
1 5/8 inches
2 inches

The size of the drain pipe that you need will depend on the size of your sink and the type of P-trap that you are using. If you are unsure of what size drain pipe you need, it is always best to consult with a qualified plumber.

Here are some additional tips for choosing the right size drain pipe for your bathroom sink:

Measure the diameter of the drain hole in your sink.
Choose a drain pipe that is the same size as the drain hole.
If your sink has a overflow hole, you will need to purchase a drain pipe that has a built-in overflow.
If you are using a P-trap, make sure that the P-trap is the correct size for the drain pipe.

By following these tips, you can ensure that you choose the right size drain pipe for your bathroom sink.