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Are Bathroom Sink Drains a Standard Size or Universal?

The most frustrating plumbing issue you may have had is with the bathroom sink. The sink drain is clogged, or the sink isn’t operating correctly, among other things.

If you are considering replacing your old sink drain, you should be aware of its size and type, as well as if it is universal or standard, or is there any catch behind it? Let’s take a deep dive into the matter.

Are bathroom sink drains a standard size or universal?

A standard size bathroom sink drain would make it easier for replacing any additional parts and a universal size would have been more convenient. However, the bathroom sink drain is available in various sizes. The most common size for bathroom sink drains is 1¼ inches, 1 ½ inch, 1⅝ inches. 

Are all bathroom sink drains the same size?

There had been a misconception about the bathroom sink drain size that it’s all the same but in reality, there are several sizes available on the market. The most common sizes available in the market are 1½ inches, 1¼ inches, 1 ⅝ inch.

You would need a perfect fit or a smaller size bathroom sink drain, if you get a bigger size then it won’t fit in the sinkhole. Although bathroom sink drain sizes are not universal and there are several sizes available in the market, a 1 ¼ inches size would be perfect for the job.

Are there different size bathroom sink drains? 

When it comes to bathroom sink drain sizes, you’d require an ideal fit or a smaller sink drain, therefore it doesn’t suit your sinkhole if you have a larger size.

The bathroom sink drain size is not universal nor is its size properly standardized, so you would find various sizes available on the market. The most widespread size variation would be the 1 ½ inches, 1 ¼ inch, and 1 ⅝ inch.

Before purchasing a new sink drain or replacing the old one, take proper measurements of the sinkhole and connected pipes. It will surely save you a lot of time and keep you from doing any excessive work or any unnecessary burden. 

What size are bathroom sink drains? What is the standard size?

There are 3 types of bathroom sink drains available in the market.

  • Grate drain
  • Pop up drain
  • Press drain

Most people believe that the sink drain size is standard and is 1¼ inches. However, when there were fitting problems and the sink drain wasn’t providing satisfying results even after a completely new replacement there were more detailed investigations.

It found that the sizes were not standardized and there was more than one size. We were sometimes getting the ideal size and sometimes buying smaller without even knowing. So it’s important to know the size and pick the best ideal fit sink drain for your installation. 

Generally, the bathroom sink is available at 1 ¼ inch, 1 ½ inch, 1 ⅝ inch, and many more. Take proper measurements of the sinkhole, the drainpipe, and all the related parts before installing the new sink.

An ideal fit would be best for the drainage system, a smaller one might fit but will bring more trouble and constant maintenance would be necessary. Unknowingly, if you are trying to fit a bigger size sink drain, then you might damage the pipe or the sink.

How to measure bathroom sink drain size?

Following few simple tips will help you to measure bathroom sink drain size –

Getting the overall measurements:

For installing a sink drain, you would need accurate measurements for the length, width, and dept. The radius of the countertop and the sink pipe. You can use tape to measure the magnitude. 

Necessary dimension information: 

The size of the drop-in sink will be designed according to the countertop. You would generally find a 15 inch to 20-inch diameter and 6inch to 8-inch depth oval shape sink available in the market.

So, the sink drain size would depend on the sink size, but not to worry as the manufacturers will design the sinkhole somewhat near to fit 1 ½ inch or 1 ¼ inch sink drain.

 Depth and sinkhole measurements:

You would need to take the depth measurement of the countertop from front to back. Now you can measure the dia of the sinkhole or sink lip, and also the dia of the sink pipe. Now you know the exact measurements.

Take those measurements to your nearest sanitary shop or depo and look for a sink drain with the perfect fit. 

Not finding the perfect size:

Sometimes you might not find your desired size sink drain. The manufacturer might have made a specific sink drain for the sink and haven’t put it on a separate sale or there is an issue with the supply chain.

No matter what the issue is, if you don’t find your desired size, you can buy a smaller size sink drain. A smaller size sink drain might not be that effective but it will get the job done.

Are bathroom sink holes standard size? 

Bathroom sinkholes are somewhat similar in size to the bathroom sink drain. The sinkhole is kept at 1 ½ inch or bigger so that sink drain installation can be done smoothly. The sinkholes are not standard size and you can blame the manufacturer for this.

They built their bathroom sink and made a sinkhole according to the sink drain they have designed. It kind of forces the customer to buy their specific size sink drain. 

What size hole to drill for bathroom sink drain? 

Actually, you would need to drill a hole in the stone or tiles you are trying to set the sink basin in. You would need to measure the outer surface of the sinkhole, the extra edge near the sinkhole to get the exact measurements to drill.

You will need to make it a little bigger than the sinkhole

However, if you are trying a DIY project and trying to install a custom-made sink, then the sinkhole you need to drill should have a diameter of around 1 ⅝ inch.

If you drill a hole in the sink with a dia around 1 ⅝ inch, it would easily fit 1 ½ inch, 1 ¼ inch, 1 ⅝ inch and almost all size sink drains available on the market.

How big is a bathroom sink drain? 

Let’s take a look at the dimensions and other measures of a bathroom sink drain to get a sense of how big it is. The length would be the first thing you would look at in a visual assessment. The overall length would be split into two parts: thread length and tailpipe lengths. 

A sink drain is approximately 8 inches long, tailpipe 5 ¾ inches, and thread length 3 ¾ inches.  Now the top, bottom, and thread dia, the top dia is 2 ¼  inch and the sink dia is 1 ½ inch and sometimes 1 ¼ inch.

The top of the sink drain is kept bigger to provide it better grip and make it hold on to the sink basin. Now the bottom tailpipe dia is 1 ½ inch or 1 ¼ inch, so the drain pipe you have needs to be a little bit bigger or an ideal fit for it.

What is the standard sink drain pipe size? 

The sink drain pipe or the tailpipe size in length is 5 ¾ inch and the dia is 1 ¼ inches. The length isn’t that much of an issue but the diameter holds great importance for getting a perfect fit.

A smaller dia tailpipe can be adjusted but if the dia is bigger than the regular sizes you are up for a great deal of trouble. 

What is the standard height of a bathroom sink drain? 

The standard height of a bathroom sink drain is between 16 to 20 inches. The water supply lines are kept at 22 to 25 inches from the floor so it’s ideal to place a sink drain at 16 to 20 inches from the floor.

How far can a sink drain be from the vent? 

For a sink drain with 1 ½ inch diameter, the vent is kept at 2 ½ feet distance from the trap. The vent shouldn’t be kept more than 3 feet from the sink drain.

Are bathroom sink aerators universal? 

The aerators have different threads and are named male aerators and female aerators and the bathroom sink aerators aren’t universal. You would find two different sizes one is a regular size and another one is junior size.

A regular size aerator will have a male aerator or male threaded faucet in 15/16  inch and a female threaded faucet or female aerator size 55/60 inch.

A junior aerator has a male threaded faucet or male aerator size of 13/16 inches and a female threaded faucet or female aerator size of 3/4 inches. 

Final Thoughts: 

For the bathroom sink drains the most popular sizes are 1 ¼ inch, 1½ inches, 1⅝ inches. So the bathroom sink drain size isn’t universal nor does it maintain a standard size. It would have been easier to make any replacement if bathroom sink drains were available in standard size.