How Far Can You Move a Toilet From the Stack? (Maximum Distance)

Written by

Paulk Webb


Freddie J. Hagopian

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how far can you move a toilet from the stack

When you remodel your bathroom, you may need to move the toilet to a more convenient location.

And if you are considering moving your toilet, you’ll come across this question: how far can you move a toilet from the vent stack?

The distance you can move a toilet from the vent stack depends on the pipe’s diameter, slope, fixture units, and local plumbing codes.

As a general guideline, it’s typically 6 feet for a 3-inch waste line and 10 feet for a 4-inch waste line.

Keep on reading to learn more.

Recommended Distances


The vent stack is typically located on the inside wall, so the distance that the toilet can be moved from the vent stack is limited by the distance between the inside and outside walls.

The specific distance from toilet to vent stack for your area may vary. It’s essential to consult with a plumber or your local building department to get accurate information before moving a toilet.

But to give you an idea, here’s a general guideline on the distance limitations for your reference.

  • The pipe should have a slope of at least ¼ inch per foot to ensure that wastewater flows freely. Therefore, to achieve this, according to IRC, the minimum distance is 6 inches.
  • The maximum distance for moving a toilet sideways depends on the diameter of the pipe.
  • For a 3-inch pipe, the maximum distance is 6 feet.
  • For a 4-inch pipe, the maximum distance is 10 feet.
  • If you move a toilet location far away from the vent stack, a vent extension pipe may be necessary to allow the wastewater gasses to vent properly.

What Factors Affect the Distance of the Toilet From the Vent?

If you want to move a toilet location, you need to know the several factors that affect the recommended distance of your toilet from the vent stack. This will ensure the proper functioning and efficiency of your plumbing system.

1. Diameter of the Pipe

The waste line is the pipe that carries wastewater, including the contents from toilets and other fixtures, away from a building to the main sewer line. The diameter of this pipe can vary, with 3-inch and 4-inch being common sizes in residential plumbing.

  • As the pipe gets bigger, it can handle more wastewater and transport it better. This means you can move the toilet farther from the vent stack without causing system performance problems.

So, if the pipe is bigger than 4 inches, you might be able to move the toilet further from the vent stack, but you’ll have to consult a plumber or your local building department to comply with the exact requirements.

2. Slope of the Pipe


The slope of the waste line is important because it ensures that the wastewater flows freely. When wastewater flows down a pipe, it creates a vortex that helps to keep the wastewater moving. The steeper the slope, the stronger the vortex and the more freely the wastewater will flow.

The minimum slope of 1/4 inch per foot is specified in the International Plumbing Code (IPC).

  • If the slope is too shallow, meaning it is less than a quarter inch per foot, the wastewater may not be able to flow effectively through the pipe. It can lead to problems such as clogs, slow drainage, water backups, and foul odors due to debris and solids settling in the pipe.

3. Building Layout


The layout of the building and the location of the vent stack may influence how far a toilet can be moved while maintaining proper drainage and venting.

In addition, the total number of fixture units in your plumbing system can influence the recommended distance. Fixture units measure the flow rate and load on the plumbing system, with each plumbing fixture assigned a specific number of fixture units.

  • A higher number of fixture units may require a closer connection to the vent stack.

Frequently Asked Questions

Does an offset toilet flange affect how far I can move a toilet from the vent stack?

Yes. The offset toilet flange can affect how far you can move a toilet from the vent stack.

Specifically, it provides a few inches (approximately 2 inches) additional, in any direction from the existing toilet sewage pipe. This extra space helps align the toilet waste pipe with the floor drain opening, even when the two are not directly in line with each other.

And in case you’re wondering, the offset toilet flange is compatible with both 3-inch and 4-inch sewage pipes.

How much will it cost to relocate a toilet?

It can range from $2,500-$5,000 for a standard relocation.

The cost of moving a toilet depends on a few things. The cost can increase if you move it far, change the flooring, or have complex plumbing needs. Keep these factors in mind when planning the project.


By now, you know the answer to the question: how far can you move a toilet from the vent stack? You have also gained an overview of the recommended distances and factors to consider if you plan a toilet relocation.

Remember, moving a toilet can be a complex and messy task. If you decide you can move your toilet on your own, plan and make sure you have all the necessary tools and materials before you start.

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