Are Toilet Seats Universal 2

Are Toilet Seats Universal? Toilet Seat Sizes Explained

It can be a pain when your toilet seat breaks or needs replacing because there are so many types to choose from. If you need to replace your toilet seat, does it matter which model you choose, and are they universal?

Toilet seats are not universal, but most models are similar. For example, most round toilet seats are the same length (17 inches or 43 cm), while most elongated toilet seats are usually around 19 inches (48 cm) long. Still, it’s crucial to always measure your toilet before buying a new seat.

Understanding more about toilet seat sizes is essential if you need to buy a new one. In this article, I’ll explain everything you need to know. Let’s dive right in! 

Toilet Seat Types and Dimensions

When you ask yourself, “Are all toilet seats the same size?” the answer is no because they come in various sizes and designs. The two most common types of toilet seats are round and elongated, and they generally come in similar sizes. However, there are newer styles (such as the d-shaped toilet seat), and those sizes can vary.

Below, I’ll discuss the dimensions of a toilet seat and the most common types:

Elongated Toilet Seat Size

If you want to replace your bathroom’s toilet seat, the chances are that you have an elongated toilet seat. It’s similar to a round toilet seat but usually a little longer and slimmer (but not always). 

As briefly mentioned in the introduction, the average length of an elongated toilet seat is around 19 inches (48 cm). However, it may be slightly shorter than this (for example, 18.5 inches or 47 cm). 

Sometimes, an elongated toilet seat can measure as little as 17 inches (43 cm). Since there’s no universal size for an elongated seat, the best thing to do is measure your toilet accurately before buying a new seat.

However, it’s easy to tell if your toilet seat is round or elongated because elongated seats have an oval or egg-shaped appearance.

Round Toilet Seat Size

Another prevalent toilet seat type is the round shape, commonly found in homes across the US and the rest of the world. These are some of the oldest styles of toilet seats and measure around 17 inches (43 cm) in length. 

Some round toilet seats may be slightly shorter than 17 inches (43 cm), so it’s essential to measure your toilet seat to get the exact length. A round toilet seat could also measure between 15 and 16 inches (38-41 cm).

Once you have the correct measurements, you can buy the round toilet seat of your choice.

U-Shaped Toilet Seat Size

U-shaped toilets are not usually found in private homes but are commonly used in public restrooms. 

As you can imagine, these seats are shaped like a “u” because there is a gap at the front. The gap at the front is for hygiene reasons so that women can more easily wipe the perineal area after using the toilet.  Since these hygiene concerns are generally not present in a home environment, you’re unlikely to need this type of toilet seat.

Still, it’s good to know the dimensions of such a seat, and the length is usually between 15 and 19 inches (38 to 48 cm). U-shaped toilet seats can be round or elongated, and the size depends on the specific toilet.

D-Shaped Toilet Seat Size

D-shaped toilet seats have a more modern appearance than round and elongated ones and are becoming increasingly popular. As a result, they’re most commonly found in newer homes or newly renovated bathrooms. 

They are called “d-shaped” because the end of the seat is curved, while the back end is straight, creating a “d” toilet seat shape.

These toilet seats can vary in length. However, they typically measure around 17 inches (43 cm) long, similar to a standard round toilet seat size. 

Square or Rectangular-Shaped Toilet Seat Size

Like d-shaped toilet seats, rectangular and square-shaped seats are newer and sleeker than other varieties and are more prevalent in newer homes and bathrooms. The terms “square” and “rectangular” can be used interchangeably when discussing toilet seats because most are not truly squares.

In most cases, they’re rectangular because the length is generally longer than the width. A rectangular or square toilet seat size can differ, but most measure between 16.5 and 18 inches (41.9 and 46 cm). Unlike d-shaped toilet seats, square or rectangular ones have straight sides, making them look sharp, contemporary, and sleek.

How To Measure for a Toilet Seat

Now that you know more about the sizes of some of the most common types of toilet seats, you may be wondering how to measure for a toilet seat. Knowing where to start the measurements will help determine the precise size you need.

Here’s a guide on how to do it:

  1. Take the first measurement. The first measurement is the length of the area, so you should place your measuring tape in the middle of the two screws or holes where the seat would screw in. In most cases, you shouldn’t measure from the very back to the very front of the toilet because the seat doesn’t go all the way to the back.
  2. Measure the width. When measuring the width, it’s best to start the measuring tape right at the edge of one side and bring it across to the other. Measure the widest part. The toilet seat you choose should cover the entire toilet area, and it shouldn’t be smaller or bigger than the toilet itself.
  3. Measure the distance between the two screws or holes at the back. To secure a toilet seat in place, you must screw them in at the back. Generally, these screws are the same distance apart on most toilets, but it’s still important to measure just in case.
  4. Take note of the measurements and buy a toilet seat. Once you have your toilet’s measurements, you can select the perfect-sized toilet seat for your bathroom.

It’s important to remember that different types of toilet seats can have the same length. However, they aren’t universal and won’t fit every toilet. For instance, a round toilet seat might have similar dimensions to a square toilet seat, but it still won’t fit on a square-shaped toilet. 

This makes taking accurate toilet dimension measurements and noting your toilet’s shape very important. 

Should a Toilet Seat Be Bigger Than the Toilet? 

A toilet seat should not be bigger than the toilet. It should be the same size to fit perfectly on the toilet. If it’s larger than the toilet, it will look odd and may make using the toilet uncomfortable. The seat may even become damaged over time due to too much weight on the ends.

When a toilet seat is too big for the toilet, it will likely stick out at the end and, therefore, won’t have support from the toilet itself at the bottom. As a result, it will be more likely to become damaged (especially if it’s made from cheap material like plastic).

Of course, you can still use a toilet if the seat is too big, but it’s always best to get the right size.

What Happens If the Toilet Seat Is Smaller Than the Toilet?

A toilet seat shouldn’t be smaller than the toilet. It should have the same dimensions as the toilet so that it looks neat. 

A toilet seat that’s too small will not only look strange but will also be uncomfortable to sit on and may break over time due to too much pressure and not enough support.

When a toilet seat is too small, there will likely be a gap between the end of the seat and the toilet, making everything look out of proportion.

A common mistake is selecting a round toilet seat that’s too small for an elongated toilet bowl. While the width might be the same, the length won’t. So, it’s always essential to make sure you get the right shape as well as the correct measurements.

Having said that, it’s fine to have a toilet seat that’s only a few millimeters smaller than the toilet. In that case, it will be barely noticeable and won’t negatively impact the aesthetics or comfort of the toilet.

Best Places To Buy Toilet Seats

It’s one thing to know the shape and measurements of your toilet, but it’s another to know where is the best place to buy the seat you need! Below is a list of the best places to buy a toilet seat, as they will likely sell all shapes and sizes:

Home Improvement and General Furniture Stores

When buying a new toilet seat, some home improvement stores are worth trying because they generally sell all shapes and sizes. One example of a home improvement store that sells many good-quality toilet seats is Home Depot, with prices ranging from as little as $20 to over $1,000.

Home Depot sells all the main toilet seat shapes, including:

  • Square
  • Elongated
  • Round
  • U-shaped

For example, it sells elongated toilet seats of different lengths, including 18 and 19 inches (46 and 48 cm). 

You can also buy toilet seats in general furniture stores like IKEA. 


Today, ordering almost anything online is easy and hassle-free, so why not consider buying a toilet seat from an online retailer like Amazon? You can find hundreds of toilet seat options, so you’re sure to find exactly what you’re looking for. No matter what shape or length you need, you’re bound to find what you need on Amazon or eBay.

However, it’s generally not a good idea to order a toilet seat online if you’re worried that the picture looks slightly different from the photo. Also, some people prefer to see these things in person before buying because they can impact the overall style of a bathroom. This is where buying a new toilet seat in-store has an advantage. 

Are Toilet Seats Always Made of the Same Materials?

Toilet seats are not always made of the same materials, but they are commonly plastic because it’s cheap, durable, and easy to clean. However, other standard toilet seat materials include porcelain and treated wood.

However, the toilet seat’s material composition doesn’t impact its size. For example, both elongated and round toilet seats can be made of wood. So no matter what material you want, taking measurements is vital.

Here are the most common toilet seat materials:


Plastic is one of the most common toilet seat materials because of its low cost. The main type of plastic used on toilet seats is thermoplastic and thermoset. Thermoset is generally more expensive because it’s more durable and long-lasting and less likely to get scratched easily.

Plastic toilet seats come in a wide range of sizes and shapes (including elongated and round), and they can also have widely differing prices.

Another type of plastic used for some toilet seats is resin, although it’s not very common anymore. 

Resin toilet seats typically have designs (like flowers) and may be more popular for younger children. They were popular between the 70s and 90s but aren’t commonly seen anymore due to their more outdated appearance.

Like other plastic seats, resin seats come in different shapes and sizes.


Porcelain is a more expensive toilet seat material because it’s more challenging to make and shape than plastic. It’s a ceramic material and is highly durable and long-lasting. Porcelain toilet seats have various shapes, sizes, and price points. 

You can find porcelain toilet seats ranging from 15 to 19 inches (38 to 48 cm).


Although wood is less common than plastic and ceramic materials, you can find wooden toilet seats in stores and online. Wooden toilet seats generally come in round or elongated shapes, but some may also be d-shaped.

Wooden toilet seats are generally sealed to ensure they don’t get damaged over time, but they’re still not as durable as seats of other materials.

Newer styles of toilet seats (like square or rectangular shapes) are unlikely to come in wood materials, so you may need to use a different material if you have a more modern toilet.


Bamboo toilet seats look like wood toilet seats, so you might mistake them for one another. Most bamboo toilet seats are round or elongated, and you’re unlikely to find square or rectangular seats made of this material.

Bamboo isn’t a widely used material for toilet seats, but some people choose it for their home bathrooms.

Which Is the Best Toilet Seat Material?

The best toilet seat material is porcelain because it’s more durable than plastic and easy to clean. Porcelain won’t stain or get damaged easily, making it a good choice if it’s within your budget. However, it’s more expensive than plastic, and many models can cost over $1,000, so they’re not always within people’s budgets.

The next best thing is plastic, particularly thermoset, because it’s durable and easy to clean. Although plastic isn’t necessarily as strong as porcelain, a good-quality plastic toilet seat should last many years. 

It’s easy to find porcelain and plastic toilet seats in all the most common shapes and lengths, so you shouldn’t have any issues finding what you need if going with porcelain or plastic.

Most public toilet seats are plastic because of their low cost and ease of cleaning.

Why Are Most Toilet Seats White?

Most toilet seats are white because it makes them easier to clean. If a toilet seat was a darker color (like brown or black), it would be more difficult to see dirt buildup, so the seat would likely get dirtier than a white one without you even realizing it. 

In addition to white being more practical due to how easily it shows dirt, it’s also beneficial because the ceramic material is naturally white. Therefore, it would take more time, effort, and money to make it a different color. 

A plastic or wooden toilet seat is more likely to be a different color because these materials are easier to dye. Most plastics are white or milky or slightly clear to begin with, so it makes more sense to make these different colors. Still, white is the most common color because it goes with everything, regardless of the theme in your bathroom.

White is generally the universal color for toilet seats.

Can You Replace a Plastic Toilet Seat With a Wooden One?

You can replace a plastic toilet seat with a wooden one if the measurements are the same. Before buying a wooden seat, measure the length, width, and distance between the two screws/holes. You may also measure the plastic seat to ensure you get a wooden one that matches the exact proportions.


After reading this article, you should understand why toilet seats are not universal. Toilet seats can come in various shapes, dimensions, materials, and colors, making it important to know what you need before you head to the store. 

They come in different shapes, sizes, and materials, so you must know precisely what you need before purchasing a new toilet seat. 

The main toilet seat shapes are:

  • Elongated
  • Round
  • D-shaped
  • Square or rectangular

Elongated seats are typically longer than round ones by a few inches. Toilet seats come in different materials, including porcelain, plastic, and wood.

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