Well Pump, Pressure & Yield

Size the water side of the well: required pump GPM / peak demand (fixtures × gpm), total dynamic head & an informational HP guide (pumping level + pressure head + friction), pressure-tank sizing (drawdown ÷ acceptance factor), a well yield / flow-rate bucket test, daily household water use, and pump & pressure-tank replacement cost. Sizing values are labeled planning conventions — a pump installer sizes from the pump curve.

Planning estimate: this is a planning estimate from the numbers you enter and standard reference quantities — not a bid or a contract. Get itemized written quotes from licensed contractors and confirm measurements before you commit.
Required Pump GPMWork out the peak GPM your well pump should deliver from the number of fixtures that can run at once. Free fixture-count sizing calculator with the formula.Total Dynamic Head & HP GuideCalculate a well pump total dynamic head from pumping level, pressure and friction, then read an informational HP tier. Free TDH calculator with the formula.Pressure-Tank SizingSize a well pressure tank from your pump run time, GPM and pressure switch. Free drawdown and total-tank calculator with the formula and acceptance factors.Well Yield / Flow-Rate TestTurn a bucket test into gallons per minute: enter the water collected and the fill time to get your flow rate. Free GPM flow-rate calculator with the method.Daily Household Water UseEstimate your household daily water use in gallons per day from the number of people plus irrigation or livestock. Free gpd calculator with the formula.Pump & Tank Replacement CostAdd up your well pump and pressure-tank replacement cost from your own line items: pump, labor, tank and wiring. Free estimate built on the prices you enter.

Yield, pressure and the bucket test

The water side of a well is three questions. How much can the well give? A 5-gallon bucket flow test — gallons collected ÷ seconds × 60 — gives the instantaneous GPM in the well yield calculator, and the flow-rate test guide explains why sustained yield needs a longer draw-down test. How much does the house need? Fixtures set peak demand (required GPM) and the household sets daily gallons (daily water use). Can the pump deliver it? Total dynamic head — pumping level plus pressure head plus friction — decides (TDH & HP).

The pressure tank ties it together: drawdown = run time × GPM, and the 20/40, 30/50 or 40/60 switch setting fixes how much of the tank is usable — size it (with the drawdown reference chart) in the pressure-tank sizing tool, and budget the eventual swap with pump & tank replacement cost and the pump-sizing guide.

Every Well Pump, Pressure & Yield tool is calculated server-side — visible immediately — with its formula, a worked example and a reference table, and works on the prices you enter. Background reading is in the guides.