Plumbing & Water Supply Calculators
Drainage and supply fixture units, septic tank sizing, rainwater harvesting and sump pump capacity — the sizing side of building services.
Plumbing & Fire Live Tool
Drainage Fixture Unit Calculator
Total drainage fixture units and the minimum building drain from fixture counts under the IPC or UPC tables.
Total DFU = sum(n x DFU) ; building drain from the code sizing table Plumbing & Fire Live Tool
Water Supply Fixture Unit Calculator
Total water supply fixture units converted to an estimated peak demand in gallons per minute and a typical service size.
Total WSFU = sum(n x WSFU) ; peak demand interpolated from the Hunter flush-tank curve Plumbing & Fire Live Tool
Septic Tank Sizing Calculator
Septic tank volume and standard size from residents, daily flow, retention time and the sediment storage allowance.
V = n x q x (t/24) x sediment factor Plumbing & Fire Live Tool
Rainwater Harvesting Calculator
Annual and monthly rainwater yield from a roof, with a cistern size derived from a daily demand and autonomy period.
V_year = A x (P/1000) x C x efficiency Plumbing & Fire Live Tool
Sump Pump Sizing Calculator
Inflow to a sump from the drainage area and design rainfall, with the safety-factored pump capacity and hydraulic power.
Q = A x (i/1000) x C / 3600 ; P = rho g Q H / eta