A house’s bathroom is a space designed for comfort and function, and your toilet is at its center. If your toilet isn’t meeting your needs, it might be time for an upgrade! 

Installing a new toilet can help you save on your electric bill too. Choosing a water-efficient toilet and other bathroom fixtures can save you an average of 30% annually!

Do any of those reasons to upgrade make you want to start your own DIY installation project? 

If so, consider purchasing a new piece of equipment and taking the first step toward installation. The first step to any successful installation is knowing all the measurements you need to make your project smooth.  

The following is everything you need to know as a DIY installer about toilet dimensions.

Toilet Bowl Shapes

Did you know there are different shapes for the bowl of your toilet? The most common types are round and elongated. Each offers varying advantages to your space. Understanding the different types of toilet bowls and how to account for them when measuring your toilet dimensions.

The following are the two major types of toilet bowls and how they affect the DIY installation process.


When you think of toilets, you most likely think of the common shape: the classic, round bowl. Depending on the make and model of the toilet itself, the bowl could have a few different dimensions. 

The standard size for a round toilet bowl is about 16 inches long and 14 inches wide. It’s vital to remember that even though the bowl itself is round in shape, it’s not a perfect circle. 

How This Affects Installation

When you install a toilet with this feature, you need to make sure you leave enough room on all sides to keep it up to code. In addition to making sure to account for the dimensions of your bowl for keeping up to code, consider your bathroom on the whole. Round toilet bowls are ideal for smaller spaces. 

If your bathroom is more compact, installing a rounded bowl toilet will make it easier for you to fit the space. Of course, your comfort in the space is a vital consideration too. You never want to be too cramped in your own bathroom!


If the toilet you want to install is more of a modern design then you likely have a variation on an elongated toilet. The average length of these bowls is about 18.5 inches. While 2.5 inches may not sound like a lot, it’s a considerable length when you account for your seat.

These sorts of toilet bowls have increased in popularity over the last few years, due largely to their comfort. The bowls allow for more distribution of your weight, leading to a more comfortable seat. Additionally, they’re helpful for those who may have mobility issues. 

How This Affects Installation

Installing a toilet with an elongated bowl requires a bit more space to keep it up to code. Since these bowls also have several different depths and heights, you’ll want to double-check your space and leave enough room for the fixture. 

Elongated toilet bowls are ideal for larger spaces that emphasize comfort. If your bathroom is a bigger space, a longer toilet might fit it better. 

Seat Heights

After you decide what sort of bowl you want for your toilet, you need to consider how tall it will be before you install it. 

As more and more toilets are being custom designed, there are more variations on the height of the fixture you purchase. The following are some height considerations for different toilets you need to know before you install.

Standard Toilet Seat Heights

There isn’t exactly one standard seat height for toilets. In the past, the distance between the floor and the seat of a toilet was about 14 inches. Today, however, most fall in the range of 15-16 inches from floor to seat. 

There are plenty of options available for customization, and private comfort toilets can be anywhere from 14-16 inches depending on preference.

Chair Height Toilets

If you’re interested in a toilet that has a bit more height than a standard one, however, you’ll have to look at installing a chair-height toilet. These fixtures range from 17-19 inches most generally. 

Chair-height toilets are ideal for taller people or people with mobility issues. You’ll most generally see these types of toilets installed in public spaces.

The reason most public toilets have this specific range of height is due to the Americans with Disabilities Act which makes 17-19 inches the requirement for public toilets. 

So, even though you may not be installing a toilet in a public space, most chair-height fixtures on the market will fall into these dimensions so that they’re accessible to everyone. 

Custom Height

Of course, as with any fixture, there is room for variation in custom toilet heights. Generally, these heights fall anywhere from 15-28 inches in height. They also come in a variety of types, including single-piece, two-piece, bidet, and others. 

When it comes to installing a custom-height toilet, you want to consider the distance between your toilet seat and any other fixtures in your bathroom.

It’s essential to look out for overhanging racks or counters. You don’t want to hit your head or have difficulty sitting or standing from your seat. Knowing your toilet’s dimensions keeps your space clear and free of hazards.

How Seat Heights Affect Installation

With many different heights to choose from for your toilet, you may be wondering how each type affects your DIY installation. The good news is that for installation purposes the height of your toilet doesn’t make too much of a difference! 

If you have or plan to install shelves or other decor above your toilet, make sure that there’s clearance directly above where you sit. You want the fixture you install to be usable, after all! 

Besides checking overhead clearance, you want to make sure that the height you choose is comfortable for you so you don’t have to reinstall a different fixture right after you finish. 

How to Measure a Toilet

As you’re preparing to do your DIY toilet installation, you may have noticed that different toilets have different dimensions. This can make it tricky to measure them consistently, especially with so many custom options out there!

Fortunately, even with the different types of fixtures, there are a few key measurement methods that are somewhat consistent. The following are the dimensions of a toilet and how to measure them.

Overall Toilet Height

When measuring a toilet’s overall height, there are two features you must consider: the tank height and the bowl height. Each of these features includes a different maximum height that you need to know before installation.

Tank Height

The toilet tank is the highest back part which stores the water and flushing mechanism. Fortunately, this part of the toilet is easy to measure. 

All you have to do is measure the distance from the floor to the top of the tank. Once you have that measurement, you want to double-check your space and verify that your toilet’s tank will fit where you intend to install it.

There are a few considerations for the tank height of your toilet. Before installing it, double-check that if there are windows or ledges, your toilet tank can still fit beneath it. You don’t want your tank higher than a window ledge because then it won’t install smoothly. 

Bowl Height

The toilet bowl has its own dimensions that can affect installation, including depth and width. For measuring your fixture’s bowl height, however, all you need to do is measure from the floor to the top of your toilet seat.

If you aren’t able to see the toilet in person, you may wonder if the toilet bowl height will be comfortable for you after installation. The easiest way to check this without being able to sit and test it is to check the bowl height measurement against yourself.

All you have to do is measure the distance from the floor to your knee. If it’s about the same as the bowl height, you’ve found a toilet that will be comfortable for you! 

Anything too short could cause you to squat uncomfortably, and anything too tall could leave you with your feet dangling over the floor. Any DIY installer knows to double-check your measurements before you start the installation.

Toilet Depth

The proper way to measure a toilet’s depth is simple. Using a measuring tape, measure from the back bottom of the fixture to the front, making sure that you keep your measurer flat for the most accurate reading. 

Toilet Width

Toilet width requires two different measurements: the width of the tank and the bowl. Here’s how to measure both of these dimensions most accurately.

Tank Width

All you have to know about the tank width is the distance from one edge to the other. Use your tape measurer to start on one side and stretch the entire width of the tank to get an accurate number.

Bowl Width

Much like with the tank portion, the width of your bowl is one measurement from side to side. Unlike your tank, you must measure your bowl at its widest points. This is usually across the middle from one side of the seat to the opposite side. 


The rough-in of a toilet is where the plumbing attaches to the fixture. When you install your own toilet, you likely already have a spot for a toilet in your bathroom. If so, measure from the wall to the center of the rough-in hole so that your toilet matches it.

In order to find the length for the rough-in for a toilet, measure from the back of the toilet to in between the two bolts that hold the toilet to the wall. 

Standard Toilet Dimensions

Below are some standard toilet dimensions to get you started. Always measure your toilet before installation! 

Standard Toilet Height

Most toilets are about 15 inches tall. 

Standard Toilet Depth

A standard toilet is about 30 inches deep. This measurement can vary depending on which toilet you have. 

Standard Toilet Width

A standard toilet is around 20 inches wide, though this can vary depending on the style and age of your toilet. 

Standard Toilet Rough-In

This length of a Rough-In is usually around 12 inches for standard toilets, but you may find a 10 or 14-inch length too. So, it’s always better to verify before installation!


Do you still have additional questions about being a DIY installer for your toilet? You’re not alone! Here are the answers to some frequently asked questions you may have considered.

  • Is a taller or shorter toilet better?

    The height of a toilet is all about preference and necessity. If you are around five feet tall, you might be better suited to a shorter one. If you’re taller, a higher seat-to-floor ratio might suit you better.

    In addition to comfort and function, you need to consider the vertical space in your bathroom. A taller toilet is better for rooms with more vertical space. Likewise, a shorter toilet is better if you have closer quarters.

    As you can see, it all depends on your needs and space availability to know whether a shorter or taller toilet is better for you!

  • What is the smallest space for a toilet?

    According to the US code of federal regulations for toilet facilities, the minimum space for a toilet is 30×60 inches. This means that in a public space, each area with a toilet must be at least this size.

    You may want to consider a more relaxed, comfortable space in residential bathrooms. These dimensions can start at 36 x 66 inches for a minimum and extend to 48×72 inches.

    Remember, though, these are only standard requirements. Your bathroom may well be larger according to your comfort and style.

  • What is the code for distance around a toilet?

    What space does the code require around your fixture? A toilet requires 15 inches out from the center on all sides. This means that a toilet must have at least 30 inches in its space to be up to code.

    The reason the code requires this space is for accessibility. It’s also generally a good idea in case of required maintenance. You want to ensure plumbers can get into where they need to in your bathroom!

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