Water management and pump sizing calculators. Browse our free water tools below — all calculators are instant, accurate, and require no sign-up.
Aquifer Drawdown Calculator — Calculate aquifer drawdown from pumping rate and specific capacity. Estimate water level decline during irrigation pumping to plan operations.
Crop Evapotranspiration (ETc) Calculator — Calculate crop evapotranspiration ETc by multiplying reference ET₀ by the crop coefficient Kc. Determine daily water use by growth stage.
Energy Cost of Pumping Calculator — Calculate the energy cost to pump irrigation water from GPM, total dynamic head, pump efficiency, motor efficiency, run hours, and electricity rate.
Pond Evaporation Loss Calculator — Calculate monthly or annual pond evaporation loss from surface area, pan evaporation rate, and pan coefficient. Plan water budgets accurately.
Pond Storage Volume Calculator — Calculate farm pond storage volume using the frustum formula from surface area, bottom area, and depth. Convert to acre-feet and gallons.
Pump Flow Rate (GPM) Calculator — Calculate the required pump flow rate in GPM from irrigated acres, application depth, and available pumping hours. Size your irrigation pump correctly.
Pump Horsepower Calculator — Calculate water horsepower and brake horsepower for irrigation pumps from GPM, TDH, and pump efficiency. Size your motor correctly.
Pump Total Dynamic Head Calculator — Calculate total dynamic head (TDH) for an irrigation pump by summing pumping lift, friction loss, and operating pressure. Essential for pump selection.
Rain Gauge to Inches Converter — Convert rain gauge volume readings to rainfall depth in inches. Supports standard 4-inch and 8-inch gauges and custom gauge diameters.
Rainwater Harvesting Calculator — Calculate rainwater capture volume from roof area, annual rainfall, and collection efficiency. Size cisterns and plan water storage for farm use.
Reference Evapotranspiration (ET₀) Calculator — Estimate reference evapotranspiration ET₀ using a simplified Penman-Monteith approach. Input weather data to calculate daily ET₀ in inches.
Water Rights Acre-Feet Calculator — Calculate water rights allocation usage as a percentage of permitted acre-feet. Track cumulative pumping against annual water right permits.
Water Use Efficiency (WUE) Calculator — Calculate water use efficiency as crop yield per unit of water applied. Compare WUE across crops, seasons, and irrigation methods in bu/ac-in.
Well Yield Calculator — Calculate well yield in GPM from a pumping test using volume pumped and elapsed time. Determine sustainable yield for irrigation planning.