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Plumbing

Fixture Unit Demand Calculator

Computes the total plumbing demand load in fixture units for toilets, sinks, showers, and appliances, then converts it to a peak flow estimate for pipe sizing. Use it when designing or auditing a building's water supply system.

Fill in the required fields to see your result.
Plumbing

Plumbing Fixture Unit Calculator

Add up the drainage fixture units (DFU) for every toilet, sink, shower, bathtub, and appliance in a building to find the correct supply and drain pipe sizes per plumbing code. Essential for new construction, additions, or remodels.

Fill in the required fields to see your result.

Key differences

Fixture Unit Demand CalculatorPlumbing Fixture Unit Calculator
CategoryPlumbingPlumbing
Inputs required55
ResultPeak Demand (GPM)Total Fixture Units (FU)
What it doesComputes the total plumbing demand load in fixture units for toilets, sinks, showers, and appliances, then converts it to a peak flow estimate for pipe sizing. Use it when designing or auditing a building's water supply system.Add up the drainage fixture units (DFU) for every toilet, sink, shower, bathtub, and appliance in a building to find the correct supply and drain pipe sizes per plumbing code. Essential for new construction, additions, or remodels.