Fixture Counts Calculator

Fixture Type	Number Of Fixtures	Multiply By Fixtures Unit	Fixtures unit
Bar Sink		x 1
Bath Tub or combinationbath/shower		x 4
Bathroom Sink		x 1
Shower Head(Each Head)		x 2
Bidet		x 1
Clothes Washing Machine		x 4
Dishwasher		x 1.5
Hose bib or sill cock(standard type)		x 2.5
Kichen sink		x 1.5
Laundry sink		x 2
Whirlpool bath or combination bath/shower		x 4
Toilet (gravity tank)		x 3
Supply outlets not listed above shall be computed at their maximum demand
3/8 inches outlets		x 1
1/2 inches outlets		x 2
3/4 inches outlets		x 3
Total Fixture Units:

Click here to get code

CALCULATING THE ESTIMATED WATER FLOW DEMAND IN GALLONS PER MINUTE (G.P.M.):

Estimate the supply demand by totaling the fixture units from the Water Customer Demand Data Table – Fixture Unit Count and then by reading the corresponding ordinate from chart below. Read chart vertically until you intersect the correct curve, then read the chart horinzontally until you read your water flow demand in G.P.M.

CURVE 1 (Top): SYSTEM PREDOMINANTLY FOR FLUSHOMETER VALVES
CURVE 2 (Bottom): SYSTEM PREDOMINANTLY FOR FLUSH TANKS – TYPICAL RESIDENCES

Introduction to Fixture Counts

Calculating fixture counts is a foundational step in the design and construction of any building, ensuring that the needs of all occupants are met in accordance with the plumbing code and building code. In spaces with fluctuating occupant loads, such as schools, determining the correct number of plumbing fixtures is especially important. The plumbing code sets out the minimum number of fixtures required for each occupancy type, based on the calculated occupant load and the intended use of the space.

For example, in Group E occupancies like schools, the occupant load is determined by the total square footage and must account for both regular school hours and additional activities that may increase the number of occupants. By following these codes, designers and builders can ensure compliance, provide adequate facilities, and create safe, functional environments for all building users.

Understanding Plumbing Fixtures

Plumbing fixtures are essential components of any building’s plumbing system, including items such as sinks, toilets, urinals, and showers. The number and type of plumbing fixtures required in a building depend on the occupancy and the calculated occupant load.

For instance, a school may require a higher number of fixtures to accommodate students and staff, with separate facilities often needed for different age groups or genders. The plumbing code outlines the minimum number of fixtures necessary for each type of occupancy, ensuring that all occupants have access to adequate facilities.

Compliance with these requirements is crucial, as insufficient fixtures can lead to health and safety issues and potential violations of building regulations. By understanding the specific needs of each space and following the code, builders and architects can ensure that every building is equipped with the right fixtures for its intended use.

Calculating Fixture Requirements

To calculate fixture requirements, the first step is to determine the occupant load for the space. This is typically based on the floor area and the number of people the building is designed to accommodate. Once the occupant load is established, the plumbing code provides tables or formulas to prescribe the minimum number of fixtures required for that occupancy type.

For example, in a classroom, the occupant load might be calculated by dividing the total area by the code-specified area per person, then using the resulting number to find the required number of toilets, sinks, or showers. The calculation must reflect the function and intent of the space—whether it’s a classroom, gym, or cafeteria—and ensure that the required number and type of fixtures are provided. This process helps guarantee that the building is designed for both code compliance and occupant comfort.

Applying Fixture Counts

Once the required fixture counts have been calculated, the next step is to apply these numbers to the actual building design. This involves ensuring that the correct number of fixtures is installed in each relevant space, such as restrooms, locker rooms, or auditoriums.

For example, a school auditorium with a high occupant load will require more fixtures than a standard classroom, as prescribed by the plumbing code. It’s important to consider the specific needs of each occupancy and verify that the required number of fixtures is both provided and properly distributed throughout the building. Proper application of fixture counts not only ensures compliance with code but also supports the health, safety, and convenience of all building occupants.

Using the Fixture Counts Calculator Tool

The fixture counts calculator tool is an invaluable asset for professionals involved in the design and construction of new buildings or renovations. By inputting details such as occupant load, occupancy type, and space area, the calculator quickly estimates the required number of plumbing fixtures in accordance with the plumbing code. This tool streamlines the process of determining fixture counts, helping architects, engineers, and builders ensure that their designs meet code requirements and provide adequate facilities for all occupants.

Whether working in schools, offices, or other occupancies, the calculator saves time and reduces the risk of errors, making it easier to achieve compliance and deliver well-designed, functional spaces.