Repair when Flushing

Choosing the right flapper for your toilet

Selecting the right flapper for your toilet is very important since the flapper valve is what regulates the water to the bowl. Fluidmaster has developed a universal design set of flappers to help stop the confusion and select the right flapper. The flapper valves we offer are categorized by Frame, Size and Type.

If you are unsure what size of flapper you will need for your toilet, please click here: Determine size of flapper

Read below to learn more about:

1. Frame: Two styles of flappers

2. Size: The actual size of the flapper ball and which size of drain it will seal properly.

3. Type: The flushing capacity, which is the amount of water used to flush the toilet bowl, that the toilet was designed to use.

4. Keys to selecting a flapper

5. Fluidmaster flappers available

1. Frames: Fluidmaster currently has two styles of flappers

  1. Flexible Frame (All- Rubber): These flappers will fit most Flush Valve Drains and the all rubber-style flappers can stretch to fit oddly sized flush valves, angled seated flush valves and flush valves that do not have mounting posts for a fixed attachment.
  2. Solid Frame (Hard Plastic Frame): The plastic frame forces the flapper ball to consistently center onto the drain to seal every time. Solid Framed Flappers are designed to stop toilets from leaking for longer periods of time. This flapper style does not work with all Flush Valve Drains; however, the key to using this one is to know what you are currently using. There is a good chance that if you are using a plastic framed flapper already then the Solid Frame can be used as a replacement.

2. Size: Currently Fluidmaster offers two sizes of flappers for the two most common size Flush Valve Drains, 2-inch drains and 3-inch drains.

  1. 2-inch flappers are available in both styles: Flexible and Solid Frame.
  2. 3-inch flappers are only available in the Solid Frame style.

3. Types: There are two types of flappers, Adjustable Flappers and Non-Adjustable Flappers, and these flappers are designed for specific flushing capacities of toilets. There are 4 main toilet flushing capacities that are commonly used in the United States today; 5 gallon per flush and larger; 3.5 gallon per flush; 1.6 gallon per flush and 1.28 gallon per flush toilets.

  1. Toilets that are manufactured from 1994 to present come in both styles and in both size categories; Adjustable flappers are designed to flush toilets that flush 1.28 and 1.6 gallon per flush (GPF) toilets.
  2. Toilets that were manufactured before 1994 are all considered to be the larger gallon per flush toilets and are still in use. Non-Adjustable Flappers are designed to flush toilets that flush 3.5, 5 and larger gallon per flush (GPF) toilets. Non Adjustable Flappers come in both Styles but only in 1 size category, 2-inch.

To learn more about your toilet’s flush volume, please click here:

Determining your toilet type

4. Keys to understanding how to select a flapper can be as easy as:

  1. Know the age of your toilet (if you don’t know, guess the age of the home).
  2. Know if the flapper has a Solid Frame or if it’s a Flexible Frame.
  3. Know the size of your flapper, 2- or 3-inch (measuring the drain hole your flapper covers will tell you the size you need).

5. If you need a 2″ toilet flapper, we recommend the 502 toilet flapper

If you need a 3″ toilet flapper, we recommend either the 513A toilet flapper or the 5403 toilet flapper

Here are some examples of the Fluidmaster flappers available.


For more available Flappers click here

To download our free guide to fix common toilet problems please click here: Fluidmaster Toilet Repair Guide