Toilet Rough-In Dimensions: How to Measure Toilet Rough-In 2022 Guide

If you do not know how to measure toilet rough-in, it may appear like replacing or installing a toilet is a difficult process. With so many different types and designs of toilets to pick from, it’s easy to become overwhelmed. The most common error individuals make when acquiring a new toilet is ordering one with the incorrect toilet rough-in dimension.

Installing a toilet rough-in that clashes with your existing bathroom set-up is useless and not possible. That is unless you are willing to spend on remodeling or new plumbing. Another issue is that most toilets cannot be returned once the box has been opened. This is done for sanitary purposes, thus you may end up having to buy a new toilet on top of ending up with a toilet that is of no use to you.

But you need not worry! With a few tips about rough-in measurements, you can select and install a toilet that is a great match for your bathroom, whether it’s in your house, workplace, or other commercial establishments. To avoid this costly and time-consuming error, I have explained the step-by-step procedure for measuring a toilet rough-in size, regardless of the toilet you possess.

You will also learn how to measure a toilet rough-in distance in this section. This is for the readers who are planning to install a new toilet. Now let us start the rough-in measurement guide. But before that, many of you may not be familiar with the term rough-in. So let’s take a brief look.

What is a Toilet Rough-In?

toilet rough-in

The distance between the bare wall and the center of the toilet drainpipe is the rough-in size of a toilet. A precise rough-in size guarantees that adequate room exists between the drainpipe and the wall for the rear of your toilet and the toilet tank to fit when fitted.

When acquiring a new toilet, the first important consideration should be measuring and determining the proper toilet rough-in. The rough-in is the location of the water outflow beneath the toilet (usually).

Continue reading for instructions on how to measure your toilet rough-in.

Standard Toilet Rough-In Sizes

When planning your bathroom layout so that you may install toilet partitions in a bathroom in a park, school, business, or other location, you must take meticulous measurements. You want your restroom customers to have enough space in each stall without wasting any valuable space. Furthermore, each restroom cubicle should be uniform in size and properly set up.

This toilet-buying guide will lead you through the usual toilet measures you should take into account when purchasing partitions:

Although the usual toilet rough-in is 12 inches, don’t assume you have one without measuring! Some older homes have rough-in sizes of 10″ or 14″. To conserve space, 10″ rough-in sizes are sometimes seen in powder rooms, half baths, and other tiny restrooms.

The unusual 14″ rough-in size provides greater space between the toilet and the wall. When compared to the usual 12″ rough-in size, you may need to specifically order either of these rough-in sizes. Some toilets, such as two-piece toilets, are adaptable in terms of rough-in size, while others are not. That is why it is critical to select a toilet with a similar rough-in size to your existing bathroom or water closet.

Any plumbing professional will tell you that a 12″ rough-in is the industry standard for both two-piece and one-piece toilets. A rough-in measurement of 10″ or 14″ is sometimes found. If it’s not one of those three lengths, you’re in for a real treat.

Seat height: Measure the distance between the floor and the top of the toilet seat. Standard toilets are 15 to 17 inches tall, whereas chair-type toilets can be up to 17 inches tall.

Shapes of toilet bowls: Round toilet bowls require less space than elongated bowls, which can be up to three inches long. Remember that you’ll need at least 24 inches of room in front of the toilet, as well as enough space around the bowl.

Toilet dimensions: To establish the needed width of each stall, measure the broadest section of the bowl or the widest part of the tank, whichever is wider. Keep in mind that you will also require some room on the sides.

Toilet Rough-In Dimensions: The rough-in dimension of a toilet is the distance between the wall behind the toilet and the center of the waste pipe. The standard rough-in measurement for a toilet is 12 inches, however, they can range from 10 to 14 inches in specific circumstances.

How to Measure Toilet Rough-In: A Step-by-Step Guide

Measure Toilet Rough-In

Some people may think that measuring a toilet rough-in may be a tricky task. But it’s actually quite easy. So much so that you don’t even need a plumber for it. You can simply take the toilet rough-in dimensions yourself.

The distance between the wall and the bolt caps at the middle of the discharge should be measured. The basic rule of thumb for clearance from the wall facing the bowl is 24″ with approximately 15″ on each side. The rough-in measurement tells you how much clearance you have and allows you to choose a suitable toilet.

How to Measure a Toilet Rough-in For a New Toilet

When there is no toilet and the floor is bare, the toilet rough-in is quite simple. If you don’t already have a toilet installed, here’s how to measure for one:

  1. Determine the placement on the floor of the drainpipe (toilet flange hole). The drainpipe will resemble a spherical hole in the floor. The toilet flange may have a white plastic coating in the opening.
  2. Measure the distance between the naked wall and the center of the toilet flange opening. For a more accurate rough-in size, if your wall has a baseboard, elevate your measuring tape so it hits the bare wall above.
  3. Examine your work. If your measurement differs from the typical 12″ or 10″ rough-in measurements, you may have measured wrongly. Remember that the tape measure should only go as far as the center of the drainpipe opening—nothing more and nothing less.

How to Measure a Toilet Rough-In For an Existing Toilet

However, there are cases when you want to measure the toilet rough-in with an existing toilet. But do not worry, it is also something that can be done easily if you follow these steps

If there are visible base bolts and caps, or if the toilet has a visible profile where the trapway route can be seen, you can readily measure this. Here’s how it’s done:

  1. Determine where the toilet is secured to the floor. Look around the base of your toilet for little bolts or covers. These are often found in the trapway on the fixture’s back left and right sides. Look for any evidence of where the toilet is bolted on the side of the toilet or where the toilet meets the floor if your toilet has a skirted design.
  2. Measure the distance between the wall and the center of the toilet’s base bolts. This will give you the rough-in distance for the toilet.
  3. Measurements should not be taken from baseboards or other moldings. If your wall has a baseboard or other moldings, position your measuring tape so that it begins just above the baseboard. If necessary, measure the width of the baseboard (from the edge to the wall) and add it to the overall measurement to ensure accuracy.
  4. Examine your work. If your measurement is different from the normal 10″, 12″, or 14″, double-check your work. You don’t want to make the costly error of getting the incorrect rough-in toilet.

How to Measure Rough-in for a Corner Toilet

Corner toilets might be more difficult to rough-in than normal toilets, so don’t worry! The instructions below will give you with exact results for a smooth installation:

  1. Determine where the toilet is secured to the floor. Look for caps or bolts at the toilet’s base to see where it joins to the floor underneath.
  2. Determine the location of the toilet flange or drainpipe. Because the present toilet covers the toilet flange (drainpipe), you must estimate its placement using the bolts you just discovered. The toilet flange will be installed in the center of the two bolts.
  3. Mark the placement of the toilet flange on your toilet. To make measuring easier, mark the centerpoint of the toilet flange using tape or another non-permanent instrument. The toilet flange is most often positioned between the toilet seat and the tank.
  4. Measure the distance between neighboring walls from the center of the toilet flange. Instead of measuring from the drainpipe to the point (corner) where your walls meet, measure from the toilet flange outward at a perpendicular, 90-degree angle toward the toilet’s left and right walls. To attain an accurate angle, use a measuring square or framing square. The rough-in size is determined by where both measures overlap at the midpoint of the toilet flange.

How to Measure Rough-in for Wall-mount or Rear-Outlet Toilets

The flushed contents of wall-hung toilets travel through the wall rather than the floor. To determine the rough-in size of a wall-mount or rear-outlet toilet, measure vertically from the bare floor to the center of the waste drain.

Mistakes to Avoid while Measuring Toilet Rough-In

When it comes to measuring a toilet rough-in, there are a few typical mistakes to avoid. You should avoid the following pitfalls:

  • Many people make the mistake of measuring from the baseboard, which is commonly found along the perimeter of a bathroom floor. This might bias your measurement by up to 1/2″ in some circumstances.
  • When calculating dimensions, remember to include the baseboard.
  • If the bolt cap on the toilet base is not centered on the discharge hole, do not measure it. You may make the incorrect assumption that the bolt cap is aligned with the center of the outlet hole, but that is not a safe bet.
  • Some believe that larger units, such as ADA-compliant and elongated toilets, require a greater rough-in. This is not correct. Some elongated toilets are designed to accommodate a 10″ rough-in, while others are designed to suit a 14″ rough-in.

Things to Keep in Mind While Measuring Toilet Rough-In

Toilet Height

Aside from the toilet rough-in dimension, toilet height (or rim height) is another parameter to consider when changing your toilet to guarantee a suitable fit in your bathroom and your comfort demands.

To determine toilet height, take a vertical measurement from the floor to the rim of the toilet. The usual toilet height is 15″, although, for comfort or accessibility, some toilets are as high as 18″-19″. Toilet height excludes the lid and seat.

Bowl width and length may also be important since they affect both space and comfort. Most toilet bowls are 14 to 14.5 inches broad, with a few exceptions reaching up to 16.5 inches.

Plumbing Codes of Your Locality

Proper clearance around your toilet is also required for comfort and compliance with plumbing codes. For example, the distance from other features should be measured from the center of the toilet flange (the same place from which you measure the rough-in to the wall) to the surrounding furniture, such as your vanity, cabinets, tub, or shower.

The normal size for a room surrounding the toilet is around 15 inches, with 18 inches being more spacious for improved comfort. Depending on your local regulations, the clearance from the front of the toilet will vary.

The International Plumbing Code needs a clearance of 21″ from the midpoint of the drainpipe forward, but the Uniform Plumbing Code demands clearance of 24″.

Other Government Regulations

A partition is a crucial factor when building a public or commercial restroom environment. In many situations, company owners become overly focused on the bathroom hardware — the toilets, basins, and hand dryers — and fail to consider the dividers, which are an essential component of any public restroom.

In reality, the American Disabilities Act (ADA) and the Occupational Safety and Health Administration both require particular criteria for business restroom design (OSHA).

Failure to follow these principles may result in litigation, penalties, and other problems for your firm. The expenses of redesigning are also high: The average cost of remodeling a bathroom is roughly $250 per square foot, plus several thousand dollars for design fees.

Frequently Asked Questions (FAQS)

What is the general rough-in of a toilet?

A typical toilet will be between 27 and 30 inches deep, with a back height of 21 to 31 inches and a width of around 20 inches. A seat height of 17 to 19 inches is required for an ADA-compliant variant. This is one of the reasons why ADA-compliant bathroom barriers differ.

When measuring space surrounding a toilet in an ADA stall, extra room for a wheelchair or an aide must also be included.

What is the most common rough-in for toilets?

While 12-inch rough-in is the most common size for toilets, you can also find outer sizes. Toilets of rough-in 14″ and even 10″ can be found in traditional homes. However, these sizes don’t leave much room for a variety of toilets since modern manufacturers usually produce 12″ rough-in toilets.

Can I replace a 10-inch rough-in with bigger size?

No. Finding a toilet that fits your existing toilet rough-in measurements is great so you don’t have to pay a plumber to update your plumbing, which might significantly raise the cost of your toilet replacement.

While a 10-inch rough-in toilet may fit into a 12-inch rough-in, the same cannot be stated for a 12-inch rough-in toilet. A 12″ rough-in toilet will not fit in a 10″ rough-in bathroom.

Do I need a plumber to measure toilet rough-in?

Well technically no. You can easily measure the toilet rough-in all by yourself. But if you are not comfortable getting all handsy (though there isn’t much to do) you can always ask a professional for help.

Final Words

The rough-in measurement is the distance between the center of the outlet and the rear wall of the toilet.

Knowing your standard rough in for toilet shopping is analogous to knowing your size when it comes to updating your wardrobe. If you really want something but it’s only available in a size that won’t fit you, it’s probably pointless.

It is not impossible to install a toilet that is closer to the wall than ideal. However, this would result in a gap between the toilet and the back wall, which some people believe would significantly detract from the aesthetics.

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