Protect Your Home From Water Leaks

Prevent catastrophic damage and high water bills

Choosing the Right Toilet Flapper

Ensuring you have the correct toilet flapper installed is vital, as it will help prevent leaks in your bathroom. If an incorrect or ill-fitting toilet flapper is installed, your toilet can not only leak and waste water, but it can cost you money as well. When visiting a home improvement store you will find a daunting variety of toilet flappers, so it is essential that you know how to purchase the right one. If the wrong toilet flapper is installed, your toilet will not flush properly, or may use more water than designed to.

Types of Toilet Flappers

There are three main types of toilet flappers: seat disk, tank ball, and rubber. Identifying what type of toilet flapper you have is as simple as removing the top of your toilet tank and taking a look.

Seat Disk

Seat disk toilet flappers are the oldest type of toilet flapper. These flappers have a small circular disk that covers the overflow pipe and prevents water from traveling through it. When the toilet is flushed, the flapper exposes the overflow pipe.

A reservoir of water is used as a weight to hold the flapper open when you flush. However, when flushed, the reservoir drains out. As a result, the flapper will close after a certain amount of time.

seat disk toilet flapper

Being that seat disk flappers are the oldest type of flapper, they have some downsides. Sometimes, these flappers are large and take up a disproportionate amount of space in your toilet tank. This not only makes it more difficult to replace, but makes finding an option to replace it even more challenging.

Tank Ball

In these types of toilets, the tank ball flapper sits on top of the overflow pipe. When the toilet is flushed, the rubber ball is lifted by a chain straight up and off of the overflow pipe. This allows water to pass through.

tank ball toilet flapper

If you have a tank ball flapper, it is important to ensure that the chain holding the ball is the correct length. If it is not, it will fail to lift the ball or prevent the ball from returning to its place. This can result in the toilet not sealing properly and wasting a lot of water.


Rubber flappers are the most common type of toilet flapper in recently manufactured toilets. These flappers work by attaching a simple cap to the overflow pipe. The mechanism of a rubber toilet flapper works similar to that of a tank ball flapper. When the toilet is flushed, a mechanism pulls a chain attached to the flapper to lift it. When the flushing is complete, the chain allows the cap to drop back into place.

rubber toilet flapper

The term “rubber” may be deceiving, as not all flappers of this variety are made completely of rubber. Sometimes, these flappers only use an outer edge made of rubber to seal tightly against the overflow pipe.

These flappers are the most common because they are the most reliable. They do have a similar downfall to tank ball flappers though. If the chain is not the perfect length, the flapper will not allow the correct amount of water in and out of the tank and may cause leaks.

Size of Toilet Flapper

While the type of toilet flapper is essential, ensuring that you purchase a replacement that is the correct size is also vital. A universal sized toilet flapper used to be the norm, but today toilet flappers can range anywhere from 2″ to 4″ in size. The size of the flapper that your toilet uses usually is determined by a couple of factors.

  • Date of Manufacture
    • More recently manufactured toilets tend to use 3″ or 4″ flappers, as opposed to 2″ flappers.
  • Gallon Per Flush (GPF) Amount
    • This refers to how much water flows in and out of the tank when the toilet is flushed. It is important to know how many gallons your toilet uses and whether it is considered full flow or low flow.
      • 1.6 and 1.28 GPF toilets typically use 3″ toilet flapper valves.
different sizes of toilet flappers

Determining Size

If you are unsure of the size of your toilet flapper, there are a couple ways you can go about figuring it out.

  • Search make and model of toilet
    • If you know  the make and model of your toilet, you can search it to find out the size of your toilet flapper.
    • If you do not know  the make and model of your toilet, check the inside of the tank for the model number. Sometimes the number is on the inside walls of the tank, and other times it is on the cover. Search this number, along with the company who manufactured your toilet to find out what size flapper is appropriate.
  • Measure it
    • The size of a toilet flapper is based off of the inside drain diameter.
    • If it measures 1 7/8″ or 2 3/8″ then you have a 2″ toilet.
    • If it measures in the 3″ range, you have a 3″ toilet.
  • Eyeball it
    • Look at the flush valve drain opening at the bottom of your tank.
      • If the opening looks about the size of a baseball or orange, you need a 2″ flapper.
      • If the opening looks about the size of a softball or grapefruit, you need a 3″ flapper.

Important Note: Installing a larger toilet flapper (3″) on a smaller drain opening (2″) will not be effective, so it is important to purchase the correct size.

Additionally, some drain openings are of a unique size and do not adhere to the standard 2″ or 3″ size. If this is the case, you may need to contact your manufacturer for the exact size of your toilet flapper.

Still Unsure?

If you are still unsure what toilet flapper to purchase, home improvement store workers are usually well versed on the topic and can help you out. Sometimes, customers even bring their old toilet flapper to the home improvement store to be sure they are purchasing the correct one. So don’t be afraid to bring your current toilet flapper in for help! It is better to install the correct one than to waste water, money, and potentially create leaks in your home.

Next Steps

If you’ve already purchased your new toilet flapper and want to learn more about how to install it, please check out our article on How to Fix a Leaky Toilet Flapper

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