10 inch Vs 12 inch Vs 14 inch Rough-In Toilet: Which One Is Standard?

In the united states, there are three possible rough-in sizes for toilets. They are 10, 12, or 14 inches. So, when you are out to get a new unit for your toilet space, you will mostly be looking at options with these rough-in measurements.

But the real question is, which one is the winner in 10 inch vs 12 inch vs 14 inch rough-in toilet models? In fact, what exactly is a rough-in measurement, and how do you measure it? Well, these are some of the things that I will talk about. So, if you want to know it all, it would be a good idea to continue reading!

What Is The Rough-In Measurement?

The rough-in is one of the critical measurements you should consider for toilets. In fact, before you even think about looking at the available models, you need to consider this thing. If you get it wrong, you will face many issues during installation. To be exact, you might not even be capable of completing the process.

So, what exactly is rough-in? In short, this measurement states the distance that is between the center of the drain hole or flange to the wall. Now, for regular toilets, you will not need to go through too many hassles. But for corner toilets, things get a little complicated. I will discuss it in detail later.

Which Rough-In Sizes Are Standard?

As I mentioned in the beginning, there are three rough-in sizes. At least there are three for the United States. However, if “standard” comes into the equation, the 12-inch rough-in would be the answer. 

Basically, if you live in a modern house, there is a high chance that your bathroom has a 12-inch rough-in toilet. And generally, older homes are more likely to have the 10-inch one. The 14-inch is not that common. But you will still find it in many homes.

That said, you can not settle on a 12-inch one thinking it will be okay for your bathroom as it is the standard-sized one. You will need to measure the rough-in and determine the exact measurement before getting a toilet.

What Makes The Rough-In Measurement So Important?

So, why is it so important to choose a toilet with the correct rough-in measurement? First, you must understand that your bathroom already has the plumbing layout ready. That means all the pipes and placement markings are already in the bathroom. This statement is true for replacing an old toilet and installing a new one.

Now, regarding the pipes, your bathroom has ones compatible with only one size. Is this valid for a home that is under construction? Not really! In such cases, you have the option to reconfigure the plumbing. However, the plumbing experts will still recommend you choose one that is right for the space.

In short, you do not have much say regarding the plumbing configuration. The experts will factor in the space in your bathroom and configure it accordingly. And that will automatically require you to get a compatible toilet with the space.

What Problems Can Arise If You Choose The Wrong Toilet Rough In Dimensions?

In essence, you need to get the correct rough-in toilet to get a flush installation. The right model will ensure the toilet tank and toilet are perfectly in place. You will not find the setup having an off angle, nor will you need to worry about making any modifications during the installation process.

Smaller Sized Rough-in Toilets

Yes, you can still make a smaller rough-in-sized toilet fit in the place. There is enough space for such a size, which makes it possible for the small-sized ones to be set in place. For example, if your bathroom is compatible with 14-inch rough-in toilets, you can get away with a model that is a 12-inch rough-in.

However, you must find ways to compensate for the 2 inches gap between the wall and the toilet. The installation will also look pretty odd, and the toilet will seem like an outcast.

Large Sized Rough-in Toilets

On the other hand, you can not even finish the installation if you happen to choose a large-sized toilet. For instance, if you bought a 12-inch model but your bathroom is compatible with a 10-inch one, you won’t have enough space for the toilet.

In such cases, you will have two options. The first would be to modify the plumbing and the walls. What about the second option? Well, as you might have guessed, the second option would be to return the toilet and get a new one.

It goes without saying that both options will waste your time and, most importantly, money. For that reason, it is much better to get the right one in the first place.

10-inch vs. 12-inch vs. 14-inch Rough-in Toilets

With all the discussion aside, let me get to the thing that brought you here. So, each rough-in toilet has distinctive traits that make them stand out. Allow me to describe:

10-Inch Rough-In Toilet

The 10-inch rough-in models were once the standard size in the US. Later, the 12-inch models took the spot.

However, it does not mean that the 10-inch models are not worth it. First, the 10-inch rough-in toilets would be the best pick if your bathroom does not have much space. In other words, these toilets can help you to save some space.

To be exact, the 10-inch models can be your only option if your bathroom space is limited. And this statement will make more sense if you plan to install toilets that have round bowls.

You should also know that the areas that follow the IPC (International Plumbing Code) will heavily emphasize the minimum space requirement. And according to IPC, the minimum space you need to have in front of the toilets is 21 inches.

On the other hand, many areas follow the UPC (Uniform Plumbing Code). According to that, you will need at least 24 inches in front of the toilet. So, in situations where the 12-inch models are legally out of the equation, you will need to resort to the 10-inch toilets.

12-inch Rough-In

So, have you wondered why the 12-inch ones overshadowed the 10-inch models? The main reason is that the 12-inch toilets have two extra inches. And that extra two inches offers much better comfort than the 10-inch models. The comfort level is highly noticeable when you take toilets with an elongated bowl into the equation.

However, that is not the only reason why you will see 12-inch rough-in toilets in most modern homes. After it became the standard, the industry started to mass produce it. That led to it being pretty common in toilet catalogs. Also, thanks to large-scale production, the 12-inch models are much cheaper than 10-inc ones.

14-inch Rough-in

Although the 14-inch models are not as common, they still see use in specific configurations. For example, the 14-inch models will be the only option for a particular bathroom if the plumbers can not place the drain close to the wall.

Now, what are the advantages of these models? Well, just like the 12-inch models, you will get added comfort. However, you need to consider that these take up a good amount of space. So, you might not be capable of incorporating them in bathrooms with limited space.

How Do You Measure Toilet Rough-In?

Before getting into how to install a toilet, you should learn how to measure the toilet rough-in. But, the thing about the rough-in measurement is that you can measure it in different situations. Why so? Well, toilets come in various styles and sizes. This variation calls for different measurement methods.

How to Measure The Rough-in For Regular Toilets Before It Is Installed

If you do not have a toilet in your bathroom, the rough-in measurement process will be pretty easy for you. All you will need to do is get a tape measure and get the distance between the back wall and the center of the drain hole.

Here, the only thing that you should factor in is that you must measure the bare wall. Finished walls will have a thick exterior, which can make you get the wrong measurement. In other words, you need to consider the stud wall or drywall, if there is any.

Moreover, you need to ensure that you do not take the measurement from the baseboard that wraps around the wall at the bottom. Sometimes, the baseboard can be extra thick. For example, there could be instances where you will find that the baseboard is close to an inch.

In such cases, measure the distance without the baseboard. Then, add the thickness of the baseboard with your calculation.

How to Measure The Rough-In For A Regular Toilet When It Is Installed

Things can be a little complicated if the toilet is already in place. However, do not worry; I will make it easier. As you can not see the drain hole, you should measure the distance between the wall and bolt caps or bolts. These bolts or bolt caps will be on either side of the toilet.

This method works efficiently as the bolts align perfectly with the center of the drain hole. And the bolts always need to be screwed into one of the sides of the toilet flange.

Now, if the toilet is in place with four bolts, you need to consider the rear bolts for the measurement. However, when the bolts are not visible, you will need to try and guess where they are situated. Take a look at other toilets to make your guesswork more accurate.

How to Measure The Rough-in for A Corner Toilet Before It Is Installed

The method to measure the rough-in for a corner toilet is a little different. Generally, regular toilets’ back faces the wall of the bathroom. But for the corner units, the back of the toilet will face the corner of the bathroom. That means you will need to measure from the closest point of each side wall to the center of the drain hole.

Now, when the toilet is not in place, things will be much easier as you can easily see and take measurements from the drain hole. Basically, in this case, you have to imagine a line running from the center of the drain hole and the corner of the wall. This is the line that you will be measuring.

Do note that the measurement will be at a 45 degrees angle from the line that starts from the center of the drain hole. And it would be a good idea to measure both sides and see whether the measurements are the same. If they are not, you did not measure the line properly.

How to Measure The Rough-In for A Corner Toilet When It Is Installed

Measuring the rough-in for a corner toilet that is in place is the hardest process of them all. But, again, I got your back!

Firstly, you should focus on the center of the drain hole. Check the bolts that keep the toilet in place to find the center out. Draw a line in between the bolts using a pencil or non-permanent market.

After that, you should draw a line directly from the center of the toilet to the corner of the wall. As both the walls meet at a 90-degree angle, the line you need to draw will be 45 degrees from each wall.

Mark the place where the line from the corner of the bathroom and the line between the bolts meet. That marking is where the center of the drain hole resides. Now, you just have to measure from that mark to the corner of the walls.

Final Words

So, in terms of 10 inch vs 12 inch vs 14 inch rough-in toilet units, the 12-inch models will take the lead as they are the standard size in the US. The 10-inch models will make the most sense when you do not have enough space in the bathroom. And finally, the 14-inch is especially for bathrooms with specific configurations.

Leave a Comment