When you hear the term “rough-in,” you may be puzzled about which rough-in is appropriate for your bathroom and how to determine a toilet rough-in.

Things like this happened to me a few years ago.

It is imperative to know the rough-in size before purchasing any toilet.

This article will provide a detailed explanation of what rough-in is, how to measure it, and what the basic differences between rough-in sizes are.

This lesson will help you to clear all of your doubts. So let’s start with the basics.

What is the rough-in of a toilet?



The toilet rough-in is defined as the distance between the wall behind the toilet and the waste outlet pipe.

It is a necessary element of any bathroom. You must plan ahead of time to install your first bathroom because it is the only thing you can do the first time.

It’s difficult to make changes while the house is being renovated. So, keep in mind that you must get it right the first time. Otherwise, it will be an added burden.

The gap between the back wall and the middle of the toilet flange is referred to as the rough-in. The middle of the toilet flange corresponds to the centre of the toilet bolts that secure the toilet bowl in position.

The standard rough-in of the toilet is 12 inches, but in the market, mainly three rough-in sizes are available
10 inch
12 inch
14 inch


10 Inches Rough-in:

If your washroom has a small space and looking for the best toilet, then a 10-inch rough-in toilet is ideal for you like KOHLER K-3851-0 Cimarron is one of the best two-piece toilets.

As you are aware, this feature reduces the space between the wall and the toilet. You can notice additional space in front of the toilet.

More than 10″ rough-in is found in older homes and offices. So, if you’re thinking about remodeling your bathroom, take measurements first.

12 Inches Rough-in:

Nowadays all brands are making 12″ rough-in toilet and it so popular. Every modern house has this rough-in toilet.

This is because a 12″ rough-in toilet is less expensive than a 10″ rough-in toilet and takes up less space. It adds a classy look to your bathroom.

All manufacturers like Toto, Kohler, American Standard, and Woodbridge are making 12″ rough-in toilets for your home.

14 Inches Rough-in:

If you want to optimize your toilet, a 14″ rough-in is an excellent choice. This rough toilet is tough to find on the market. There is a very minimum stock of this toilet.

If you want to buy it, you’ll probably have to order it. However, some manufacturers are manufacturing it.

Now you’ve got an idea about what is toilet rough-in, but the question is how to determine the toilet rough-in? Right.

Don’t worry; we will solve it step by step method.



How to measure for a 10 inch or 12-inch rough-in for a toilet?


Measurement of a toilet rough-in is not a difficult task. It would be best if you had tape and some space throughout the area.

The measurement is different for three toilets
Standard toilets
Corner toilets
Rare toilets

Measuring Standard toilet rough-in:

In standard toilets, take a tape and measure the gap between the toilet flange and the back wall. You will get probably your answer. It is the best process before installation any toilet.

The toilet flange cannot be seen if the toilet is installed. You must measure the distance from the wall to the centre of the base bolts. You have an idea for your rough-in.

Measuring Corner toilet rough-in:

In the case of a corner toilet, it’s a little bit difficult to measure rough-in size. The process is also different.

First, drag the measuring tape in both corners of the commode to the middle of the bolt caps to record the positions.

Second, draw perpendiculars from both points using a straight edge tool. The location of the toilet rough-in will be where each perpendicular connect.

Measuring rare toilet rough-in:

Rare toilets have a unique rough-in position as well.

The garbage does not pass via the floor drainage system in this case. The drainage system is integrated into the wall.

Here you have to measure the distance between the polished floor to the middle of the drainage pipeline.

I think this information helps to measure your toilet dimensions.

Our pro tip is to make sure your wall is flat while measuring the distance. If you have a decorative wall, the measurement may change; a variation of 1 inch can vary your rough-in. So, before you do that, double-check it.


How to install a 10-inch rough-in toilet?


Suppose you are sure about your rough-in before purchasing a toilet. In that case, the installation process is the same for any floor-mounted toilet.

Compared to other toilets, the 10″ rough-in bathroom is easier to install, saving you money because plumber fees are too high. You only need a few essential components.

You simply follow the manual’s instructions. We also suggest a step-by-step procedure for your comfort.

Firstly check, do your toilet has a drainage pipe on 10″ rough-in. If no then install the drainage pipe. Now check your toilet have a wax ring. You must place it on the drainage pipe’s face.

The bolt-holding ring should be placed near the wax ring on the surface.

Then, position the bolt so that the threads face the toilet you want to set up.

Lower the commode slowly to match it with the wax ring and bolts. Check that the wax ring is securely in place; otherwise, leakage will occur.

Tighten the nuts after ensuring that everything is in its proper place. That secures the entire setup.

Now attached supply line and check other things. After finishing all setup, check there is any leakage problem or not.

Now connect the supply line and double-check everything else. After you’ve completed all of the setups, make sure it doesn’t leak.

Now your toilet is ready to use.

Recommended:- Troubleshooting for unclogging toilet when nothing works without Plumber


FAQS On Rough-In Toilets and Their Differences


Q1. What is the difference between 10 inches and 12 inches of rough-in?

The main difference is closet flange is near the wall in 10″ rough compare to 12″.
10″ Rough-in toilet tank is smaller compare to 12″ because of space.
A 10″ rough toilet is more expensive compare to 12″.

Q2. Can you replace a 10-inch rough-in toilet with a 12-inch rough-in toilet?

The answer is yes. You have to change the closet flange with the offset flange.
You have to do lots of work and need an expert for this procedure.
I will suggest just return your 12″rough toilet and bringing a new 10″ rough toilet. It will save you money as well as time.

Q3. What is standard toilet rough-in size?

Nowadays, 12 inches rough-in is the standard size for any bathroom. It is less expensive compare to other rough-in.
What tool is perfect for measurements of rough-in?
The measuring tape is ideal for rough-in measurements.
Purchase a tape with a metal hook at the top for the best measurements. It will allow you to perfect your measurements from the flat wall.
You can get it from any shop for a maximum of ten dollars.

Wrap Up


Rough-in plays a big role to purchase a toilet. If your bathroom has a small space and wants to adjust with rough-in, then go with 10″ rough-in.

If you are interested in buying a 10″ rough-in toilet, then check the best 10-inch rough-in toilet dominating the market.

Not only is rough-in, but there are also some major factors to consider before purchasing any toilet, such as round or elongated bowl, water consumption, flushing power, price, and so on.

But the suggestion is whatever you want to buy before that, double-check your rough-in size that will help in the easy installation process.

Keep shopping and designing your bathroom with the best toilets according to your plan, and read our article to eliminate all of your bathroom headaches.