Today’s toilet dimensions are relatively standardized, and discerning bathroom connoisseurs like yourself have two distinct choices: round and elongated toilets. Both have advantages and disadvantages, and their loyal factions. No matter which type you purchase (or already have), don’t worry; we offer a range of bidet seats and attachments to fit both types of toilets.

Dive into our toilet size guide to learn all you need to know about throne dimensions – and a little more.

How to Tell If a Toilet Is Round or Elongated

If you can’t quite tell the difference between round versus elongated toilet shapes, it’s likely because you haven’t seen a round toilet in a while. In the US, elongated toilets are much more popular. If your home was built after the 1970s or recently remodeled, there’s a good chance you have an elongated toilet.

The biggest difference between an elongated toilet and round is the shape. At a glance, elongated toilets are a longer oval shape and more pointed in the front, while round toilets are rounder and shorter from front to back.

To be sure, check out the measurements of an elongated toilet and round toilet below.

Read more: How Do Bidets Work?

Elongated Toilet Dimensions

Elongated toilets are larger and considered more comfortable than round toilets. When viewed from above, it’s usually very easy to spot an elongated toilet bowl because it’s more of an oval shape. To measure your elongated toilet bowl dimensions, measure from the toilet seat bolts to the front of the toilet bowl. The standard size of an elongated toilet is 18.5" or 470mm as measured from back to front. The width may vary.

Are All Elongated Toilets the Same Size?

No, not all elongated toilets are identical. To be considered elongated, they must be 18.5” from the bolt holes to the front of the toilet bowl, but they can range in size across most other dimensions.

Elongated toilet sizes vary by:

• Depth, as measured from the front of the bowl to the rear of the tank
• Width, as measured by the outside edges of the seat as well as the toilet bowl itself

Because all elongated toilets are 18.5" from bolt hole to front of bowl, nearly all elongated toilet seats will fit, and that includes our bidet toilet seats. 

The Benefits of an Elongated Toilet

The most important benefit of an elongated toilet is comfort. The long bowl provides more seating space and additional thigh support. There are other advantages, too. For example, elongated toilet bowls:

• Are easier to clean
• Have a larger bowl area for less “missing”
• Provide easier access for individuals with limited mobility (more on that later)
• Come with more options and features, mostly because they’re more popular

Are Elongated Toilets Better than Round?

Wondering what’s better, a round or elongated toilet? Many people prefer elongated toilets due to their added comfort and other benefits. However, round toilets are still around for a reason: they’re perfect for smaller bathrooms.

The standard sizes of toilet seats: 

Read more: The (Many) Parts of a Toilet, Explained

The Best Bidets for Elongated Toilets

If you’re looking to enhance your bathroom experience, there’s nothing quite like adding a bidet seat or attachment. Nearly all of our models are compatible with most common toilet seat sizes for elongated toilets, but these are the top-sellers:

• BB-2000: Our flagship bidet toilet seat, the BB-2000 offers a host of features, including a warm air dryer, heated seats[SN1] , and a nifty remote control.
• Pearl S400: No electricity and nearly effortless installation, the Pearl S400 is one of our newest bidet attachments and an immediate customer favorite.

Round Toilet Dimensions

Round toilet seats are more traditional and usually a part of older homes. Round toilet sizes offer the benefit of a slightly smaller footprint, saving precious space in smaller bathrooms. Round toilets do not appear perfectly round, but they’re easy to identify by their specific back-to-front measurement. Measuring from the toilet seat bolts to the front of the bowl, the dimensions of a round toilet are 16.5" or 419mm from back to front.

Are Round Toilets (and Seats) Universal?

They are effectively universal because all round toilets must meet Americans with Disabilities Act (ADA) and International Building Code standards. They must be 16.5"” from the bolt hole to the front of the toilet bowl, and the distance between the bolt holes must be 5.5". That makes all round toilet seats universal, but the other toilet dimensions may vary slightly by design. They may have a larger or smaller footprint, taller or shorter tank, or other design features that alter some of the toilet’s dimensions.

The Benefits of a Round Toilet

Think small but mighty. Round toilets offer homeowners some important advantages, especially if bathroom space is limited:

• They take up less space in small bathrooms
• They are often better for children, especially during potty training
•  They are often less expensive than elongated toilets, although there may be fewer options for features, styles, or colors

Can You Put an Elongated Toilet Seat on a Round Toilet?

If you ordered the wrong size toilet seat and want to make it work, don’t. Technically, it will fit, but you’ll have a 2" overhang that may cause the seat to bend, crack, or fail over time. It will also be unsightly and more difficult to clean. It may be a serviceable short-term solution, but make sure you get the correct toilet seat size installed as soon as possible.

The Best Bidets for Round Toilets

We make most of our top bidets with round toilet seat dimensions as well as elongated – we don’t want anyone to miss out on the fun. If you’re looking for just the right fit, check out our in-depth compatibility guide, or take the Bidet Quiz to find your bathroom soulmate.

Best Round Toilet Bidet Seat

BB-1000: They don’t call it “Supreme” for nothing. The BB-1000 Supreme packs in a host of creature comforts, including adjustable water pressure, seat sensors, and a heated seat. At $399, it might be the best value bidet seat on the market!

Best Bidet Attachment for Round Toilet

SlimEdge: While any bidet attachment will fit your round toilet, don’t overlook the SlimEdge. Its sleek, low-profile design makes it a subtle upgrade without skimping on an accessible control panel and simple installation.

Are There Standard Toilet Sizes?

Many of the questions we get from customers are focused on compatibility with toilets and bidets. Most toilets are categorized as either round or elongated, and these toilet bowl shapes have standard dimensions, making it easier to find the right bidet seat or attachment.

Only the seats follow standard toilet dimensions, but other toilet measurements fall into these common ranges:

• Toilet seat depth (as measured from the bolts to the front of the bowl): 18.5 inches for elongated seats and 16.5 inches for round seats
• Toilet height (as measured from the floor to the top of the tank): 29 to 31 inches (73cm to 79cm)
• Toilet width (as measured from the widest point when viewed from the front): 14 to 16 inches (35cm to 40cm)
• Height to seat (as measured from the floor to the top of the toilet seat): 16 to 17 inches (40cm to 43cm)
• Depth (as measured from the front of the toilet to the back of the tank): 28 to 32 inches (71cm to 81cm)

Toilet Dimension Requirements

While the dimensions of toilets do offer some options when it comes to look, length, and other factors, the United States has one important regulation when it comes to standardization. As noted previously, the Americans with Disabilities Act (ADA) specifically mentions toilet seats.

The ADA requires the following:

“The seat height of a water closet above the finished floor shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum measured to the top of the seat. Seats shall not be sprung to return to a lifted position.”

Find Your Bathroom Buddy for Life

Understanding elongated and round toilet sizes is a big step toward choosing the right bidet seat or attachment. There are also a range of luxurious features to choose from, including heated seats, occupant sensors, and deodorizers. Take our Bidet Quiz to meet your match, or get in touch for help measuring and confirming your toilet seat dimensions.