Toilet Flapper Types & Sizes Guide

Different types of toilets have different flappers designed to work with them. The right flapper helps in preventing leaks in the toilet which will lead to the wastage of water and can also destroy the whole toilet. If your toilet has the wrong flapper, it won’t flush as required and can use more water than needed. Some flappers even lead to the phantom flush which is when the toilet flushes itself without anyone touching it.

Checking the type of flapper you have on your toilet is as easy as removing the cover then looking at it. If yours is broken, you might need the help of a specialist to fix it. However, you can easily fix it with the right procedure for your type of toilet.

Besides the type of toilet flapper, you need to know its size, the flapper frame, the quality of materials, and any extra features which may make the toilet user experience better. Below, we take a look at some of these features and what to look for in a toilet flapper.

Types of Toilet Flappers

The main types of toilet flappers are the seat disk, tank ball and rubber flappers. You can easily see which one you have once you open the cover of your toilet tank. Still, you need to know their details which are as follows:

Seat disk flapper

Seat disk flappers are some of the oldest types of toilet flappers and they’re made up of a circular disk covering the overflow pipe. This circular disk has the role of preventing water from traveling through the overflow pipe keeping the toilet leak free in the process.

Seat Disc Flapper
Seat Disc

When you flush the toilet, the flapper opens up thus exposing the overflow pipe and allowing water to run from the toilet tank to the toilet bowl. In this state, the flapper is held open by a water reservoir.

This reservoir drains out when the toilet is flushed leading the flapper to close again. The toilet tank will then fill up with water.


Although a widely used type of flapper, the seat disk flapper has the following downsides:

  • They can be quite large and thus take up large amounts of space in the toilet tank. This space could’ve been used to store more water and to make the toilet flush more effectively.
  • They’re difficult to replace owing to their large size and complex mechanisms.
  • They’re being phased out hence tougher to find on the market.

Still, seat disk flappers are among some of the most reliable owing to their use in many toilets in old buildings.

Tank ball flapper

The tank ball flapper has a ball attached to a chain which is in turn attached to the flushing lever. The ball of the flapper sits on top of the overflow pipe thus keeping water from flowing to the toilet bowl. It’s a simple mechanism which keeps the overflow pipe shut when the toilet isn’t in use and open when you flush it.

Flapper Tank Ball
Flapper Tank Ball

When you flush the toilet, the chain lifts up the ball off the overflow pipe allowing water to flow to the toilet bowl. As the flushing lever is released after flushing, the ball drops back to the top of the overflow pipe blocking it and allowing water to fill up the toilet tank.


Some of the downsides to a tank ball flapper include the following:

  • It has delicate mechanisms such as a chain that needs to be of an exact length to work.
  • The chain can easily get stuck leading to leaks from the toilet tank as the toilet flush valve will remain open.
  • The mechanism can easily fail leading to leaks from the tank and a wastage of water.

The tank ball flapper is a good flapper although it has a few weaknesses which can make it quite unreliable.

Rubber flapper

The rubber flapper is the most common and most reliable toilet flapper currently on the market. It combines the features of the above two flappers and improves on them for a watertight and reliable seal which opens and closes accurately.

Rubber Flapper

While it’s called a rubber flapper, it’s not necessarily made of rubber as many other materials are also used. However, rubber is often used to give it a watertight seal.

The rubber flapper is made up of a part of the flapper which is anchored and another moving one.

The moving part has a chain attached to it and it made up of a disk on top with a ball on its underside. The ball on the lower side closes and opens the overflow pipe as one uses the toilet.

When not in use, the ball closes the overflow pipe. When the toilet is flushed, the disk and ball section are lifted up thus allowing water to rush into the toilet bowl.

The advantage with having an anchored side of the flapper is that it aligns the ball to always close the overflow pipe. The rubber flapper also suffers from the same issue of having a chain which can get stuck and needs to be of the right length to work properly.

Rubber flappers are among the most reliable toilet flappers you can get on the market.

How to Choose a Toilet Flapper

If your current toilet flapper isn’t in the best of conditions and you’re looking for a replacement, you should consider the following aspects to get the right replacement:

The type of flapper

This one is quite obvious. If you’re to replace a rubber flapper, for example, you’ll need a rubber flapper as its replacement. Unless you make modifications, you can’t change the type of flapper on your toilet or replace it with another type.

The size of the toilet flapper

A while back, there was a universal size for toilet flappers. Nowadays, however, toilet flappers have specific sizes which need to be adhered to for them to work properly. Today, toilet flappers often range between 2 and 4 inches in size depending on other aspects. These aspects include:

The date of manufacture

Old toilets make use of flappers at 2 inches in size while recent ones have flappers measuring either 3 or 4 inches in size.

The gallon per flush (GPF) amount

The gallon per flush is the amount of water which flows in and out of the toilet tank each time you flush it. For this one, there are either full flow or low flow toilets with the full flow toilets have more water than the low flow options.

Often, toilets with 1.6 and 1.28 GPF will use 3” toilet flapper valves. Those with lower flows will have smaller flappers.

Finding the right size

If you’re unsure of the size of your toilet flapper, you can check it in the following ways:

Do an online search of the model of the toilet

If you already know the model of your toilet, you can simply check it online to find out the size of the toilet flapper it uses. If you don’t know the model, you can check for the model number inside the toilet tank or on the cover of the toilet tank. You can also search for the manufacturer who may have listed the flapper size on the details of the toilet.

Physically measure it

To find the size of a toilet flapper, measure the inside part of the drain with a tape measure. The inside diameter of the drain will determine the size of the toilet flapper as follows:

If the diameter is 1 7/8 inches, or 2 3/8 inches, the toilet flapper is 2 inches.

If the diameter is 3 inches or close to it, the flapper is 3 inches.

Look at it

Sometimes, a simple look will do it for you. If the drain pipe opening is about the size of an orange or a baseball, the flapper will be 2 inches wide. If the opening is about the size of a grapefruit or a softball, the flapper will be 3 inches wide. This method is only tentative as you’ll need to measure the valve opening for an accurate measure.

Flapper frames

There are two types of flapper frames as follows:

Flexible frame (all-rubber frame) flappers

The flexible frame flappers can fit onto most flush valve drains as the rubber they’re made of allows them to change shape to the needed flush valve drain. Being made of rubber also allows them to flush valves without mounting posts and those with seated flush valves.

Solid frame (hard plastic frame) flappers

The solid frame flapper won’t fit any other flush valve drain unless it’s the same one as the one being replaced. It’s meant to provide a tighter seal and for longer period than a flexible frame flapper. Often, solid frame flappers are of the tank ball type which makes them much more reliable.

Quality of materials

You must look for a high-quality toilet unit if you expect it to last. The most important parts to check when it comes to flappers include the following:

The flapper’s body

The body of the flapper needs to resist damage by water, rush and mold. For this reason, materials such as silicone, rubber and plastic or their compounds are used as they can withstand being submerged in water for long periods of time.

An extra step that’s welcome is having an antimicrobial and antifungal layer to keep off mold. This ensures that the flapper is both strong and durable.

The cord’s quality

The cord is the lever-link between the flapper and the flush arm. It has to be of a high quality to avoid easily breaking as you’ll need to replace the whole flapper if this happens.

The Flapper Closing Time

The flapper closing time helps determine the amount of water you can save with your toilet. The best toilet flapper features to use for this purpose include the following:


This is an added and adjustable float around the chain whose position determines the speed at which the flapper closes. In this way, it’ll determine the amount of time the flapper will stay open after each flush. Basically, the longer it stays open, the more the water that’s used in a flush.

A ruler

A ruler can be an added feature which allows you to scroll the dial on the device till you attain the desired size of the gap. Essentially, the smaller the gap is, the longer it takes for water to fill the flapper and the longer it’ll take to flush it.


There are some toilets which come with several plastic grommets that fit at the bottom of the hole each with a different opening size. The smaller holes take longer to fill and seal the tank and thus have a longer flush time.

Any one or a combination of these features can help you conserve water in your toilet.

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