11 Toilet Flange Sizes & Types (Which One Do You Need)

A toilet flange is a hardware component that connects your toilet and drain pipe through the floor. There are many toilet flange sizes and materials to choose from based on your household needs. The decision of which toilet flange to buy doesn’t have to be an intimidating one. 

Toilet flanges come in 4×3-inch and 3×3-inch varieties. There are also one-size flanges that lock into place by force and odd-size pieces to fit  specific measurements. Material options are metal (copper, brass, aluminum, stainless steel, and cast iron) and plastic (PVC). In this article, we’ll address how to choose a flange and clarify which one you need. 

What is a Toilet Flange?

A toilet flange is a pipe fitting located between the toilet and plumbing system below it. Also referred to as a “closet flange,” this component serves two main purposes. 

Toilet Flange

The first is connecting the toilet itself to the ground. This secures it in place and prevents any movement or sliding. The toilet flange also fastens the toilet to the drain pipe it needs to function properly. 

Toilet Flange Shapes

There are three main toilet flange shapes, not included in the list of 11 types. These are known as regular, offset, and deep seal flanges. 

It’s essential to understand these variations before jumping into all the different types of flanges. By learning the regular, offset, and deep seal shapes, you can begin to understand which toilet flange will best suit your project. 

Regular Flanges

A regular toilet flange is differentiated from the others by its measurements. The standard, or “regular,” size for a toilet flange is 4 inches by 3 inches. 

More specifically, the 4 inch measurement is located at the top of the flange. The bottom portion measures slightly smaller at 3 inches to fit the connecting drain. 

Regular Flanges

In terms of shape, the standard toilet flange is round on the top and bottom. It extends in a straight, vertical line downward to connect both components. 

Offset Flanges

Unlike a regular toilet flange, an offset flange provides flexibility in the positioning of your toilet. Whereas the previously explained regular flange was created for the toilet to be centered in the same location of the existing pipe, an offset flange gives room for the toilet to be installed several inches on either side. 

Offset Flanges

As a result, the offset flange has a slightly deformed shape. It’s still round on the top and bottom pieces, but it’s formed in a zig-zag with the center pipe connecting the two pieces at an angle. 

Deep Seal Flanges

The final type of toilet flange is a deep seal flange. As the name suggests, this type of hardware connects the toilet even further into the pipe. 

Deep Seal Flanges

This particular flange extends about 12 inches downward, securing the deepest connection possible. It looks most similar to the regular flange, with a longer bottom portion. 

Toilet Flange Sizes 

In addition to the shapes of toilet flanges, there are various sizes available to suit each application. After deciding on the shape that works for your installation, you will need to choose the right size to fasten your toilet to the ground securely. 

Refer to the sections below to gain an understanding of common toilet flange measurements and the scenarios they are typically used for. 

Standard 4×3-Inch Flanges

As previously mentioned, standard toilet flanges measure 4 inches by 3 inches. This is the most widely available toilet flange you will find at the hardware store and online. 

The flange itself is round in shape, and extends vertically in a straight line. It’s designed for standard toilets that are installed directly above the drain pipe in the water closet. 

4×3-Inch Flanges

The bottom portion measures 3 inches in diameter to connect to a standard-sized drain pipe, and the 4-inch top section fits most toilets perfectly. If you plan on installing a regular toilet in a normal position, you will most likely be able to use a standard flange. 

The other options come into play with special requirements for your installation. These may include a toilet that doesn’t follow standard measurements or an alternate water closet layout that incorporates the toilet further away from the pipe. 

3-Inch Flanges

3-inch toilet flanges measure evenly at 3 inches on the top and 3 inches on the bottom. They are similar in appearance to the standard 4×3 inch flange, with one less inch on the bottom portion. 

A 3-inch flange cannot be used for a standard toilet, as the connector portion measures 4 inches. A flange that’s an inch too small will result in a wobbly seat after installation. Instead, 3×3 inch flanges are ideal for alternative toilet options with 3-inch connectors to the floor. 

Push-Tite Flanges

Push-tite flanges are an increasingly durable option for toilet installations. There is no standard size or set of measurements for this type of flange. Instead, it’s worked into the openings by force to fit each application, hence the name “push-tite.” 

Push-tite flanges

This type of flange works best when durability is desired. With a push-tite flange, any exposure to chemicals or excessive heat won’t cause damage. 

Odd-Sized Flanges

Odd-sized flanges are the ideal choice for specialized toilets that don’t fit standard measurements. When your toilet doesn’t have a 3 or 4 inch opening, you may need a flange that can fit anywhere from a half inch larger all the way up to 8 inches in total diameter. 

If all of the above flange types won’t fit your toilet, you will need to search for an odd-sized flange to suit your needs. A professional contractor can help you locate the right flange for your toilet if you need assistance. 

Types of Toilet Flanges

Along with all of the different sizes and shapes available for toilet flanges, there is an extensive range of materials to choose from. Depending on your household needs, you may choose brass, copper, aluminum, or stainless steel, to name a few. This section will provide you with a detailed list of toilet flange types and descriptions to help you make the right decision for your home. 

Brass Toilet Flanges

Brass is a metal alloy material, meaning it’s not 100% metal. Instead, it’s mixed with an additional material, which in this case, is a combination of zinc and copper, although it may contain other elements. 

Brass is commonly used in construction projects and home applications like toilet installations. This choice of material comes with many benefits, from high durability to rust-resistance. It also resists heat and is easy to install due to its malleability.  

Brass Toilet Flanges

You can find brass flanges for your toilet in the regular (4×3 inch) size, along with the offset and deep seal varieties. Because it’s such a popular material, these products are available at most hardware stores and online retailers. Brass is a relatively cost-effective material at an average price of $15-25 for one flange. 

Stainless Steel Flanges

Stainless steel is another metal alloy made of iron and chromium. In general, it comes at a higher price than PVC products, but it’s also highly durable and resistant to corrosion. You can expect minimal rusting on stainless steel material throughout its lifetime. 

Stainless Steel Flanges

Stainless steel provides a more secure connection between the toilet and pipes below when compared to plastic. Just like brass flanges, you can find stainless steel in standard, offset, and deep seal sizes. The average cost of a stainless steel toilet flange across large retailers is $15. 

Polyvinyl Chloride (PVC) Flanges

PVC is a synthetic polymer of plastic. This widely-produced material is extremely popular for its cost-effectiveness and versatility in toilet installation applications. In fact, the majority of homes use PVC for toilet flanges and the drain pipes below. 

When it comes to toilet flanges, the material can be 100% PVC from top to bottom, or a combination of different materials. For example, some brands incorporate pieces of metal at the top, while still using PVC to connect the pipes at the bottom. 

Polyvinyl Chloride (PVC) Flanges

PVC toilet flanges are generally manufactured in the standard (4×3 inch) and 3×3 inch sizes. The final price will depend on the size you choose and any additional material components. Overall, these flanges can be found at any hardware store for as low as $10. 

Copper Toilet Flanges

Copper is a ductile metal, meaning it conducts heat and electricity well. This makes it a great option for a durable toilet flange. 

Copper is another popular option that is widely used in many homes for toilet installations. Like many of the options on this list, the material is rust-resistant and flexible during installation. 

Something that makes copper stand out against the other metals is its bacteria-resistance. Copper is attractive to many homeowners, due to its natural ability to keep unwanted germs away from the toilet area and deter pests. 

Copper toilet flanges are available in standard and 3×3 inch sizes. The average cost of a copper flange is $50. However, you should keep in mind that this type of toilet flange will require additional components for the pieces to properly fit into the pipes due to the its rigid surface. 

Aluminum Toilet Flanges

Aluminum is a malleable metal material with a silver appearance. It comes with a naturally light and shiny finish, and provides a better alternative to plastic ror the environment. 

Aluminum Toilet Flanges

Aluminum is one of the strongest and most durable materials you can select for your toilet installation. It comes in right under steel in terms of strength, which makes this a great option for a long-lasting toilet flange. Depending on the chosen variety, the average cost is $40 between large retailers. 

Cast Iron Flanges

Cast iron flanges are compatible with cast iron pipes only. As a result, depending on pipe material, this option is not relevant for every installation. 

Cast iron is the most classic material for toilet flanges. It was used from the beginning of production, and is still applied in many homes today. It’s another highly durable material that lasts for several decades after installation. 

Another bonus that cast iron flanges provide is a high level of resistance to damage. This material is a great choice because, along with how difficult it is to crack, many issues can be repaired instead of replaced. Therefore, most issues over time can be fixed by calling a professional instead of paying for an entirely new flange. 

If you need a cast iron flange for your toilet installation project, you can find one for an average of $50 online or at your local hardware store. They are available in standard and odd-sizing ranges depending on the brand and retailer you choose. 

How Do I Know Which Toilet Flange to Buy?

Your decision of the best toilet flange to buy will depend on the size and position of your toilet, along with the material the drain, waste, and vent (DWV) pipe is connected to. 

Your new flange should match the material of your existing DWV pipe. For instance, a cast iron pipe is only compatible with a cast iron flange. The same concept applies to PVC plastic, copper, and all of the other materials mentioned previously. 

Another important factor to consider is the size of your toilet’s connector. Most standard toilets available at your local retailer will require a regular 4×3 inch flange to connect it to the ground. 

When it’s time to gather your installation materials, measure the diameter of this opening on the bottom of your toilet. This will help you determine if one of the standard sizes, such as 4×3 or 3×3, will work for you, or if you need to seek out an odd size. 

Lastly, the position of your toilet will play a large role in the type of flange you need for successful installation. Standard toilet flanges extend in a straight vertical line, and are intended for toilets that are positioned directly above the drain pipe. If you plan to install your toilet off to the side in either direction, you should seek an offset flange. 

Metal vs. Plastic Toilet Flange

The final consideration you should take into account before choosing your toilet flange is the material. So, what is the best option between metal and plastic toilet flanges? 

The answer to this question will, again, depend on the material of your existing DWV pipe. Your new flange must match what is already there for compatibility. If you’re replacing an existing flange, this is an easy choice, as the pipe will help you determine what you need to buy. 

If you’re installing a brand new toilet or DWV pipe, you may have a choice between plastic or metal. In this case, you should understand that PVC or plastic is widely available and cost-effective, but not as durable as metal. 

Metal toilet flanges are resistant to corrosion, heat, and chemicals. Although they come at a higher price, metal flanges are dependable and able to withstand almost any circumstance for years to come. 

Overall, the best choice of toilet flange for you will be determined by the toilet you are installing or repairing and the existing plumbing system underneath it. For additional help making a purchasing decision, seek assistance from a professional in your area. 

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