How To Measure A Toilet Rough In : Easy Steps

Are you looking to purchase a new toilet for your new accommodation or you want to replace your old toilet with a newer one? In both cases finding the right bathroom for home use isn’t an easy task. It is so because a lot of designs, sizes, shapes, and styles of the toilet are available in the market. Also, they come up with different built-in materials.

Fortunately, with a few simple measurements, you can easily pick the required toilet for your own house, office, or guest toilet. The first step should be to understand which toilet style is suitable for your needs, and placing it in your bathroom requires the next level of skills.

It would help if you learned what builders call the measurement of toilet Rough-In. Moreover, it comprises the toilet’s flanges distance from the fence. Carry on reading to know how to measure a toilet Rough-In so you can pick the right bathroom.

Three fundamental toilets Rough-In dimension

A toilet Rough-In directions the toilet over the water opening under the toilet. Besides, the Rough-In measurement is the distance of the water pipe’s center from the wall behind the toilet. They usually come in three basic dimensions: 10 inches, 12 inches, and 14 inches. Further, 12 inches is the most common among all. But it doesn’t mean you have to buy this size of a toilet at any cost; get the one which fits your bathroom.

10-inch Rough-In toilet:

If you have limited space in your bathroom because your residence is so small or you have an older home, the maximum chances are your toilet Rough-In is 10-inch. Most of the time, this size is not so good for many bathrooms of large size. Besides, it is okay if the size of the bathroom is less as it takes less space.

12-inch Rough-In toilet:

No doubt the most common size of toilet Rough-In is 12-inch as many buildings and homes are set up this manner. Moreover, this size is not so big and not so small. That’s why it is an ideal size if you don’t want to commit the mistake of buying too big or small a toilet Rough-In.

14-inch Rough-In toilet:

As 12-inch is the industry standard side of toilet Rough-In, it is sometimes not perfect if the gap of the water tank and the wall. That’s why the 14-inch toilet Rough-In is there to help you. Moreover, if you aim to lessen the gap of the wall behind the toilet and the water tank, then this size is perfect.

Toilet Rough-In measurement you should have to know:

There are few measurements you have to make before buying a toilet Rough-In.

  • The distance of the toilet’s flange from the wall behind the toilet
  • Where the cold water supply line to be positioned
  • Clearance from right to left
  • How much room you have in the front of the toilet’s bowl

Measure the toilet’s flange distance from the fence:

Measurement of the toilet Rough-In will save you from a mess and keep your precious time as well. You may want to have a measurement of a wall from the toilet flange to be 12 inches. Always remember that you should never calculate the length from base molding.

Don’t ever forget to measure the thickness of the wall if you are going to measure from stud walls. Chiefly, the drywall adds half an inch in most houses and apartments; therefore, the calculation of toilet Rough-In from the stud wall will be 12½ inches.

Toilets also come in 10 and 14 inches in size, and always remember that fact to get the right one for your bathroom.

Clearance from right to left:

When measuring the toilet Rough-In dimensions, it is good to calculate the toilet’s center to clearance from the sidewall. In general, the measurement is 15-inch.

But we know that some toilets are of large size. When measuring the toilet, Rough-In leaves at least 15 inches from the left and 15 inches from the right.

For example, if a tub, wall, and bath vanity is close to your toilet, then you are required to have a minimum of 15 inches of clearance from the center of the wall.

The space in the front of the toilet’s bowl:

It would be best if you considered another measurement of the distance from the toilet’s front to any object it confronts. The area in front of the bowl also relies on the plumbing code. If your regional jurisdiction is under the international Plumbing legislation, then a minimum of 21-inch of the gap is required.

However, you may need a 24-inch or more gap if your regional jurisdiction is under the Uniform Plumbing legislation. It is measured from the toilet front to the wall, or any object comes against it.

The cold water supply line position:

No matter if you are installing a new toilet or replacing an older one, the direction of your cold water supply line is the essential thing. Water supply lines are different in size and length. Therefore, if you desire to purchase a new toilet, then knowing how to measure a toilet Rough-In is a prerequisite.

Is there any formula to calculate where to locate a cold water supply line? Yes, we have a simple and straightforward procedure for knowing where to position the cold water supply line.

Just calculate 6 inches from the middle of the toilet’s flange and 7 inches above the nd. Most pro plumbers say that it’s the perfect height that suits most sizes of toilets.


We conclude this post with the hope that it has helped you in guiding how to measure the toilet Rough-In. However, if you want to get the perfect toilet for your bathroom, then follow the guidelines given above. Moreover, if you are going to buy a new toilet for your bathroom, then you can take advantage of the facts and findings given above. If you have any problem related to this article, you can comment in the comment box.

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