Home How to measure the right size of a toilet flapper?

How to measure the right size of a toilet flapper?

Installing a good flushing toilet is bothersome without setting the right toilet flapper. The perfect measurement of a toilet flapper’s size is vital for having a good bathroom. Everyone wants to look at his bathroom beautifully. So, they buy the most beautiful toilet seats, faucets, and other products of their ability. But, the toilet flappers are not related to having a beautiful outside because it stays inside the toilet tank. The flapper has a significant relation with the toilet tank. It controls the flushing system of the toilet. When the flushing is complete, water has to stop flowing because there is no need to rush water from the flush after cleaning the toilet bowl. So, when the flushing is completed, the flapper controls the water and stops water flow into the bowl. 

Different Types of Toilet Flappers

There are many kinds of toilet flappers. We can differentiate the flappers in types, sizes, and many other categories. However, you can buy a flapper which is suitable for use. Choosing the most appropriate flapper is so essential. The mistake in selecting a flapper is so severe that the bathroom setting depends on it. The flapper in the wrong size measurement can not fit in your bathroom. So, it is the most important work to collect the best flapper in size before setting it in the toilet. toilet flappers

Generally, we find three toilet flappers: seat disk, tank ball, and rubber. There are some mentionable characteristics of both the flappers. You have to judge which flapper is the best for fulfilling your demand. 

Seat Disk Toilet Flapper:

 replace seat disk toilet flapperThe flappers made of a circular disk are seat disk toilet flappers. They are covered with the overflow pipe to open up for run water during flushing. Seat disk toilet flappers are the oldest ones. There is a reservoir of water, and it increases a little bit of the weight of the flapper. When you flush the toilet, the weight holds the flapper open and completes the working process. Then the flapper closes again and gets ready for the subsequent flushing. 

Cons of Seat Disk Toilet Flapper:

  • The seat disk flappers are large. As a result, they spend more space on toilet tanks. If the flapper could be smaller, the tank might hold more water inside and flush the toilet bowl more forcefully. 
  • The seat disk flappers are the oldest ones, and now they are extinct from the market. Although they have some positive characteristics, they are hard to find in the market. 
  • The mechanism of the seat disk flapper is so critical. So, it is hard to repair it. The large size of the flapper also made it hard to replace. 

Tank Ball Toilet Flappers:

There is a chain attached to the tank ball flappers. When you flush, the chains connect to the flushing lever. The ball of the flapper sits on the top of the overflow pipe. Thus it restricts the water going to the toilet tank. 

Toilet Tank BallThe straightforward mechanism is easy to understand. The chain allows the ball to lift off the overflow pipe. Then the water flows into the toilet bowl and flushes the toilet entirely. When flushing is complete, the flushing lever releases. After that, the ball goes to the top of the overflow pipe by dropping. The dropping ball allows the water to refill the tank and prepare for the subsequent flushing. 

Cons of The Ball Toilet Flappers

The ball toilet flappers are not so large as the seat disk flappers. Still, there are some downsides to these flappers. 

  • The mechanism of the ball toilet flappers is related to the tank’s leak. The leak is reliable for the wastage of a vast amount of water. The leak also causes the toilet valves to remain open, expending more water than necessary. 
  • The subtle mechanism made the chain of the flapper complex. If the chain does not get an exact length, it can not work correctly.

Rubber Flappers:

Rubber Toilet FlappersToday the most popular and perfect toilet flappers are rubber flappers. If you search for the most common toilet flappers in the market, you will get these. These flappers are an impressive combination of the two flappers mentioned above. Additionally, rubber flappers are watertight and reliable seals that stick to water firmly after flushing. They are durable also. 

Do you think the rubber flappers are made of rubber every time? It is not necessary because it is just a name. But, mainly, the rubbers are used to make its strong seal. The incomparable feature of rubber makes the seal watertight. This feature made the flappers the most reliable ones. 

After flushing the toilet, the balls of the rubber flapper close the overflow pipe and stick tightly. Lifting the disk and the ball is the following process after flushing. They allow the water to fill the toilet tank and prepare after the subsequent flushing. 

There is no significant disadvantage of rubber flappers. As the most common and newest flappers, the manufacturers of modern toilet sets mainly use rubber flappers. 

How to Choose the Perfect Toilet Flapper Size?

The available toilet tanks have a 2-inch or 3-inch drain, so the flappers must come in the same size. Both the 2-inch and 3-inch flappers are available. But, sometimes it is hard to find the 3inch ones. 

Do you know how to measure the correct dimension of the flapper? First, remove the flapper which is inside the toilet tank. Now, notice the flush valve and measure it. It has been exposed to the tank. 

The 3-inch toilet flappers are universal ones. Most of the toilet tanks now take the 3-inch flappers. They are longer than the 2-inch flappers and are not prone to tear. The 3-inch flappers are reliable for the efficient flushing of a toilet. 

There are also 4-inch flappers in the American standards. They are not as perfect as the 3-inch flappers, but they still exist in the toilet markets. The 3-inch flappers are standard for setting with every toilet tank in this generation.  

How to Measure The Toilet Flapper?

After having sufficient knowledge about a toilet flapper size, the fact comes with measuring the toilet flapper. There are some different tactics for calculating the flappers which allow you to get an idea about the present flapper of your toilet tank. 

  • Using A Standard Ruler

As the most uncomplicated process, using a ruler is the best for measuring the toilet flapper. Anyone with little knowledge about numbers can easily calculate the flapper with a ruler. There is a little problem with using the instrument. You will seldom get the correct measurement if you can not hold and place the flapper with the ruler while measuring it. The alignment of the standard rulers with the holes of the plastic hinge is difficult. If you can not align them properly, you can not get the correct result. 

  • Using A Metal Ruler

The metal ruler is perfect for measuring the size of a toilet flange. Do you know how it is possible? You can easily calculate the flange with the metal ruler because you can line up the ruler with the plastic hinge holes. But, you do not need to turn the flapper valve. So, the alignment of the metal ruler with the plastic hinge is easier. It allows you to get the accurate size of your toilet flapper. How To Measure The Toilet Flapper

  • Measure with Paper, Tape, and Water

First, cut a square sheet of paper and make sure that the square is thicker than the toilet paper’s height. Now open the toilet bowl’s interior, take the piece of paper, and attach it to the inner part of your toilet bowl. The paper must be stuck with the toilet bowl as it gives you an accurate measurement. 

The toilet bowl contains a significant amount of water. So, use the tape to stop water from entering the bowl. Now, place the paper inside the bowl and notice how much of the piece remains. Now, take the paper out of the toilet tank and measure it. The paper measurement will give you the actual size of the toilet tank. 


Being the essential instrument for flushing the toilet, a flapper is not ignorable. If you can not match the proper size of your toilet flapper, you can not buy it correctly. Moreover, the 3-inches flappers will give you tension-free flushing with the modern toilets. So, be careful about the perfect measurement of the toilet flapper. You can also take some important advice from the plumbers as they are experienced. Getting a vast amount of knowledge about the toilet tank and flapper can make you confident in collecting the best one in your bathroom.

Hi, this is Robert Crossan, the owner of this website, has 17 years of experience in the installation, maintenance, and repair of toilets and plumbing systems. After completing the Level 2 Basic Plumbing course in 2005, I started working in both domestic and commercial buildings as a professional plumber. So I can figure out the core difference between different toilet models and brands. It also helped me monitor their work performance and setbacks.


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