plumbing Calculators
Last updated: May 2026
Pipe Flow Rate Calculator
Calculates the volumetric flow rate of water through a pipe in gallons per minute.
Water Pressure Loss Calculator
Calculates friction-induced pressure drop along a water pipe using the Hazen-Williams equation.
Septic Tank Size Calculator
Estimates the minimum septic tank capacity needed for a household based on bedroom count and daily water usage.
Drain Pipe Slope Calculator
Calculates the required vertical drop for a drain pipe based on its length and diameter to ensure proper self-cleaning flow.
Water Heater Size Calculator
Estimates the recommended water heater tank capacity in gallons based on household size and hot water usage habits.
Pipe Insulation Thickness Calculator
Estimates the required insulation thickness for a pipe based on its diameter, the temperature difference between the pipe and surroundings, and whether the pipe is indoors, outdoors, or in a crawl space.
Faucet Flow Rate Calculator
Calculates a faucet's flow rate in gallons per minute (GPM) by timing how long it takes to fill a known container.
Toilet Flush Volume Calculator
Computes the volume of water used per flush by measuring the internal dimensions of the toilet tank.
Grease Trap Size Calculator
Determines the required grease trap (interceptor) capacity in gallons based on the number of connected fixtures, their individual flow rates, and the required grease retention time.
Pipe Expansion Joint Calculator
Calculates how much a pipe will elongate or contract due to a temperature change, accounting for the thermal expansion coefficient of steel, copper, or aluminum.
Water Heater Sizing Calculator
Determines the minimum tank capacity (in gallons) your household needs based on occupants, bedrooms, bathrooms, usage pattern, and heater efficiency.
Drainage Pipe Slope Calculator
Calculates the required slope and total vertical fall of a drainage pipe to achieve self-cleaning sewage flow over a given horizontal distance.
Septic Tank Sizing Calculator
Estimates the minimum septic tank volume (in gallons) needed for a home based on bedroom count, occupants, plumbing fixtures, and daily wastewater generation.
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.
Water Meter Sizing Calculator
Determines the appropriate water meter size (in inches) for a property by comparing peak flow demand against the meter's rated capacity at the available line pressure.
Grease Trap Sizing Calculator
Determine the minimum grease trap size (in gallons) for a commercial kitchen based on sinks, dishwashers, meal volume, kitchen type, and required retention time.
Pipe Friction Loss Calculator
Calculates pressure loss (in PSI) due to pipe friction using the Hazen-Williams equation, given flow rate, pipe length, diameter, and material.
Pipe Flow Velocity Calculator
Calculates water velocity (in ft/s) inside a pipe from flow rate and pipe diameter, then checks whether it falls within code-acceptable limits for the selected application.
Water Pressure Drop Calculator
Calculates the residual water pressure (PSI) at the end of a piping run after accounting for elevation changes, pipe friction loss, and fittings.
Plumbing Fixture Unit Calculator
Calculates total plumbing fixture units (FU) for a building by summing standardized load values for toilets, sinks, showers, and tubs.
Hot Water Recirculation Calculator
Estimate the heat loss in a hot water recirculation system based on pipe length, diameter, insulation quality, and acceptable temperature drop.
Sump Pump Sizing Calculator
Determine the minimum sump pump capacity (GPH) needed to protect your basement given its area, local peak rainfall, soil drainage, and discharge lift height.
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.
Water Pump Sizing Calculator
Calculate the required pump power output in horsepower given flow demand, total dynamic head, and pump efficiency.