Can You Replace A 14 Inch Rough In Toilet With A 12 Inch Rough In Toilet

Can You Replace A 14 Inch Rough In Toilet With A 12 Inch Rough In Toilet?

The rough-in measurement is something you must critically consider whether you are replacing your toilet or remodeling the entire bathroom. While you will have difficulty installing your toilet without the proper measurements, can you replace a 14-inch rough-in toilet with a 12-inch rough-in toilet?

Ideally, the rough-in of your toilet should match that of your bathroom plumbing. However, you can install a 12-inch rough-in toilet into a space designed for a 14-inch rough-in toilet. On the flip side, a 14-inch rough-in toilet will not fit the area designed for a 12-inch rough-in toilet.

To distinguish between these toilets, you must know how to measure a toilet’s rough-in. This information will ensure your toilet fits its designated place. 

Keep reading to find out more.

What Is The Rough-in Of A Toilet?

This refers to the distance between the drain line center and the bathroom’s rear finished wall. The standard toiler rough-in is 12 inches, but some toilets have rough-ins of 14 inches or 10 inches, so it’s paramount to know your toilet’s rough-in measurement.

When measuring your toilet’s rough-in, do it on a finished wall rather than a stud wall or baseboard since that will give you an error of at least ½ inch depending on your wall type. 

Besides measuring the distance, you can also check inside the tank for the model number of the toilet then search online for its specification sheet to get the rough-in. 

See also How to fix cracked toilet seat

Can You Replace A 14 Inch Rough-in Toilet With A 12 Inch Rough-in Toilet?

You can replace a 14-inch rough-in toilet with a 12-inch rough-in toilet, but you will be left with 2 inches of space between the wall and the toilet tank. It’s worth noting that vice versa is impossible, meaning you cannot replace a 12-inch rough-in toilet with a 14-inch rough-in toilet.

Moreover, a toilet with a rough-in of 10 inches can be installed in a rough-in space of 12 inches. However, a 12-inch rough-in toilet won’t fit into a 10-inch rough-in space.

The replacement choices are limited when it comes to a 10-inch rough-in toilet because you can only replace it with a toilet with the same rough-in. 

If a gap between the bathroom wall and the toilet tank bothers you, you must find the exact match with your old toilet when looking for a replacement. 

The extra 2 inches left between the wall and the toilet when you replace a 14-inch rough-in toilet with a 12-inch rough-in toilet won’t affect its functionality. However, it increases the distance between the shutoff valve and the toilet tank, so you may need a more extended connector to reach the valve effectively.

In addition, you will need to stretch your hands further back to reach the toilet paper if the holder is mounted behind the toilet. You will likely have to consider relocating it to a more easily accessible spot.  

See also Best 3 inch inside fit toilet flange

What Is The Difference Between 10-Inch, 12-Inch, And 13-Inch Rough-In Toilets?

As mentioned earlier, toilets come in rough-ins of 10 inches, 12 inches, and 14 inches, and it’s important to know the difference. 

10-Inch Rough-In Toilet

You will likely find it in older homes or if your bathroom can accommodate the size. Due to the small space, these toilets have round front toilet bowls, and the number of toilets with 10-inch rough-in is minimal.

12-Inch Rough-In Toilet

This is the standard and most popular toilet rough-in measurement, with its size and structure accommodating various bowl shapes and toilet styles. However, despite its popularity, don’t forgo measuring the rough-in before buying a new toilet. 

Current toilet plumbing uses this dimension, with most toilets sold having 12-inch rough-in. An excellent example of such a toilet is the American Standard 2462.016.020 Cadet Elongated Pressure Assisted Two Piece Toilet with an elongated bowl.

The American standard 2462.016.020 has a 2 1/8 inch fully glazed trapway, combination tank and bowl, and a Chrome trip lever. It has a recommended operating pressure of 25 psi to 80 psi, with its ever-clean surface inhibiting stain growth and odor-causing mildew, bacteria, and mold.

In addition, its water consumption rate is 1.6 Gallons Per Flush.

14-Inch Rough-In Toilet

You will often find this toilet in older homes and households’ small bathrooms. The toilet options in this category may be limited.

If you are looking for a 14-inch rough-in toilet, consider Kohler K-3948-RA-0 Wellworth Elongated 1.28 gpf Toilet with 3-bolt installation. It offers excellent flushing performance, and it’s designed to complement your bathroom design bring elegant flare. 

In addition, it doesn’t take up a lot of space, is easy to install, and has a water consumption rate of 1.28 gpf; thus, it conserves water without compromising performance. 

This toilet is also available in rough-in dimensions of 10 inches and 12 inches, so it doesn’t limit you to the 14-inch version. 

Read also Toilet with largest trapway

How To Measure A Toilet Rough-In

Before measuring, you will need to gather the necessary tools for the job: paper, pencil, and a ruler or measuring tape. Organization and preparation are critical to the success of this task, so don’t rush into it and measure multiple times to ensure the measurements are precise and consistent.

With a measuring tape, find the distance between your bathroom’s finished wall to the flange bolt halfway point or the bowl’s base bolt cap halfway point. You can also measure from the wall to the center of the flange opening if you haven’t installed the toilet yet. 

Avoid measuring from the baseboard as that will give you an error of a few inches, depending on the type of wall. Write down the measurement on a piece of paper and repeat the process just to be sure. 


While you should attempt to match your toilet’s rough-in with the bathroom plumbing rough-in, it is possible to replace a 14-inch rough-in toilet with a 12-inch rough-in toilet. 

Regardless, make sure you measure the rough-in of your toilet to be sure; after all, it’s pretty straightforward that you don’t have to hire a plumber for the job. 

See also How to protect bathroom floor from urine 

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