How to relocate a toilet safely and systematically

Looking to remodel your bathroom? One of the most dramatic changes you can make is to move the toilet. While it sounds like a daunting project, changing the toilet’s position can greatly improve your bathroom’s layout and functionality. But it raises a lot of questions: how to relocate a toilet, and should you even move it? If so, how far? And how much does it cost?

In this comprehensive guide, we’ll break down everything you need to know about how to relocate a toilet, including tips on adjusting drain lines and what to consider before you start smashing tiles.

Can you actually move a toilet?

Yes—you absolutely can move a toilet. But how far and how easily you can move it depends on your current plumbing setup.

For small adjustments (say, a couple of inches), you might not even need to drill a new hole in the floor. In these cases, an offset toilet flange can do the trick. An offset flange lets you shift the toilet slightly in any direction without completely rerouting the plumbing. It’s a cost-effective solution if you’re just trying to tweak the bathroom layout.

However, if you’re planning to move the toilet more significantly—say, to the other side of the bathroom or even to a different room—you’re in for a much bigger project that involves new toilet drain lines, floor work, and possibly changing the vent and water supply.

How far can you move a toilet?

Theoretically, you can move a toilet as far as you want, even to another floor. But the further you move it from the main stack (the vertical pipe that connects to your home’s sewer system), the more complex—and expensive—the job becomes.

Here’s a good rule of thumb based on the drain line size:

If your waste pipe is 3 inches in diameter, you can move the toilet up to 6 feet from the stack.

If it’s 4 inches in diameter, you may be able to go as far as 10 feet.

Any move beyond these distances will likely require a new waste line with an appropriate slope. This is essential to prevent toilet sewage smells and ensure everything flushes as it should.

What about cast iron pipes?

If your existing plumbing uses cast iron pipes, relocating a toilet gets trickier. Cast iron is durable but notoriously difficult to cut and modify. You’ll probably need a professional plumber with specialized tools and experience. Working with cast iron can also increase your costs by up to 40%. So, budget accordingly.

How does the flange help move a toilet?

The toilet flange is the connector that attaches your toilet to the toilet drain. When moving the toilet, you’ll need to install a new flange at the new location. The flange must be level, sealed tightly, and aligned with the drain line to avoid leaks and odors.

If you’re only shifting the toilet a little, an offset flange (as mentioned earlier) could be your best friend. It can move the toilet by up to 2 inches in any direction without changing the drain layout.

What does it cost to move a toilet?

Moving a toilet isn’t a budget DIY project. Here’s what you can expect to spend:

• Basic relocation (no major changes to vent or water lines): $2,500–$3,500
• Full relocation (new water supply, venting, and floor plumbing): $4,000–$6,000
• With cast iron pipe modifications: Add 30%–40% more

These cost estimates can vary depending on labor costs in your area and the complexity of the project. If you’re doing a full bathroom remodel, it might make sense to include the toilet move as part of the bigger picture.

Pro tip: Use a bathroom remodeling cost estimator to get a more accurate picture of what your dream bathroom will cost, including relocating fixtures like your toilet.

What are the key factors to consider before moving a toilet?

Before you tear into your tile, here are some essential components to plan for:

Toilet drainage

The toilet drain must connect to the main sewer stack at the right slope—typically 1/4 inch per foot. Too steep, and solids may stay behind; too shallow, and water may not flow properly. Getting this slope right is critical to avoid clogs and unpleasant odors.

Tip: If you’re unsure how to adjust the slope, consult a licensed plumber. Gravity-based drainage systems must be installed with precision.

Vent pipes

Vent pipes prevent a vacuum in your plumbing system, ensuring your toilet flushes smoothly and quietly. When relocating a toilet, you must also realign the vent pipe to match the new toilet flange and drain lines.

Skipping this step can lead to sluggish flushing and—you guessed it—toilet sewage smells.

Water supply lines

The water line that feeds your toilet will need to be rerouted. This is usually easier than drain line modifications, but must still be properly sealed to prevent leaks. Don’t forget to shut off the water and drain the pipes before beginning any work.

Flooring and structural access

If your bathroom is on the second floor or above, relocating a toilet means accessing the subfloor and possibly cutting through floor joists or opening up the ceiling below.

Some considerations:

• Cutting joists may weaken the structure—consult a contractor.
• Concrete slab floors require jackhammering.
• You’ll need to patch the flooring and possibly re-tile.

Do you need a permit to move a toilet?

In most cities, yes. Because moving a toilet involves plumbing work and can affect your home’s drainage system, a permit is often required. Inspections ensure that the plumbing meets code and there are no issues down the line. It’s best to check with your local building authority to confirm requirements.

Can you move a toilet yourself?

If you’re experienced in plumbing and construction, a minor toilet relocation might be manageable as a DIY project. But anything that involves moving drain lines or cutting into the floor is best left to professionals.

Hiring a licensed plumber ensures that your bathroom project is done correctly, safely, and up to code.

What are the alternatives to moving a toilet?

If the cost or complexity of moving the toilet seems overwhelming, here are a few workarounds:

• Use an offset flange to shift the toilet slightly.
• Redesign the bathroom layout around the existing toilet.
• Install a rear-discharge or upflush toilet system, which uses a macerator pump and doesn’t rely on gravity drainage. Such a setup is ideal for basements or unusual layouts.

How to relocate a toilet: Key takeaway

Relocating a toilet can completely transform your bathroom’s layout, making it more functional and visually appealing. However, it’s a complex project with many moving parts—drain lines, vent pipes, the toilet flange, water supply, and floor structure all come into play.

Before starting, ask yourself: Is the layout change worth the cost and complexity?If the answer is yes, go ahead! Just make sure you plan carefully, hire the right professionals, and secure necessary permits. A well-executed toilet move can add comfort, efficiency, and even value to your home.

Written by Billy Guteng. January 30, 2020

Billy is a content writer for Kukun. He was born in France, and has lived in multiple cities around the world ever since. He loves art, design and architecture as well as construction and real estate.