Fixture Unit Calculator (DFU / WSFU)
How many fixture units is a toilet?
Under the IPC, a residential flush-tank water closet is 3 DFU for drainage; under the UPC it is typically counted as 3–4 DFU. A flushometer (commercial) water closet is higher, often 6 DFU. On the water-supply side a tank-type toilet is about 2.2 WSFU. Always use the table that matches your adopted code and whether the use is private or public.
Run the numbers for your project
Use the Fixture Unit Calculator (DFU / WSFU) to get an exact answer for your inputs.
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