What Size Vent Pipe for Toilet? [A Perfect Measurement]

what size vent pipe for toilet
A vent pipe is important to help the toilet pass water and other waste properly. But so many users are truly confused to get the actual vent pipe size for a toilet. Are there any hidden things to measure the vent pipe for the toilet?

Or, what size vent pipe for toilet? It is typically recommended that a 2-inch PVC pipe for the vent. It is a standard measurement but not mandatory to do. Note it may not be enough because it depends on the fixture, which means how many fixtures you are trying to run off the vent.

However, if you are still confused about getting the question-answer, you can check out the following detailed information so that you can get a clear answer. So, without talking more, let’s get started with the article.

What Size Vent Pipe for Toilet?

Most of the toilet plumbers used a 2-inch PVC pipe for the vent to install the toilet. Though they told me that the size is not static, that means it is versatile. They also told me that the vent size is depended on the fixtures.

Moreover, the plumbers think that the vent pipe for the toilet is properly designed for a 2-inch PVC pipe. So, before measuring the vent size for the toilet, you should decide how many fixtures you are using for the toilet.

How Far Can a Toilet Be from a Vent Stack?

According to UPC, the distance between vent and trap should be a maximum of 6-feet. Besides the measurement of the vent distance, you should also ensure that the drain line is within 6 feet of the tramways that connect to it.

You may never go up to 6-feet distance from the trap because of its smooth working system. The draining system also needs to maintain the measurement so that the toilet properly maintains the distance from a vent stack.

How to Vent a Toilet Sink and Shower?

If you want to vent a toilet sink and shower, you need to use feed 2″ PVC from the ceiling with the wall behind the toilet. The vent pipe is also needed to connect to the toilet drain pipe. In this section, you need to be careful because of creating pressure.

Moreover, the sink drain pipe and the shower faucet drain pipe are vented with a 1.5″ pipe that branches off from the 2-inches PVC pipe. Are you still confused about this matter? If your answer is yes, let me know in the following comment box.

Plumbing Vent Size Chart (Maximum distance of fixture trap from the vent)

From this chart, you will get a perfect distance between the fixture trap and the vent. I strongly believe that this chart is ready to clear your confusion. So let’s break down the following table to know the actual vent pipe size for the toilet.

[ninja_tables id=”160″]

FAQs (Frequently Ask Questions)

Q: Does a toilet need a 3-inch vent?

Answer: It depends on toilet fixtures. How many fixtures do you need to use? If you think that you need to use so many fixtures, you can use a 3-inch vent. Or, the fixtures are not so many; you can use a 2-inch vent.

Q: How big should a vent pipe be?

Answer: The pipe vent should be 2-inches. According to UPC, a 2-inch vent is enough for a toilet. But, it is also true that the vent pipe size also depends on the fixture.

Q: What size vent does a bathroom need?

Answer: The standard vent size of the bathroom is 2-inches, and you can go for a maximum 3-inch vent size for your bathroom. On the other hand, you should care about the fixtures because the fixtures help you to understand which size vent you need to use for the bathroom.

Q: What size pipe do you run to a toilet?

Answer: You can use a 2-inch PVC pipe to vent to urn a toilet without facing a single problem. So, you can select a 2-inch PVC pipe or also choose a 3-inches maximum PVC pipe for your toilet.

Q: Can you use a 2-inch pipe for a toilet?

Answer: Of course, you can use a 2-inch pipe for a toilet without getting any errors. But, it would help if you also kept in mind the fixtures. You may need to increase the size of the fixtures are so many.


I think this information is enough for you to use the perfect vent size for the toilet. You can use a 2-inch or 3-inch vent for your toilet. Similarly, it would help if you focused on the fixtures because it helps you to understand which size vent you need to use. Do you have any questions or queries about this matter? You let me know in the following comment box.

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