Irrigation Pump & Pipe Sizing Calculator
Hazen-Williams friction loss, total dynamic head, pump HP, and energy cost per acre-inch
Check irrigation mainlines and pump concepts using Hazen-Williams friction arithmetic. Enter flow rate, pipe material, diameter, length, fittings, elevation, source lift, pump efficiency, and electric rate to estimate TDH, water horsepower, shaft horsepower, velocity, and cost per acre-inch. Treat the output as an estimate that still needs pipe-product data, pump curves, NPSH, surge, water-rights, electrical, and qualified irrigation review.
Size the electrical panel and service entrance for the pump motor, VFD, and any pivot controls.
Ag Electrical Load Panel Planner →Budget diesel fuel storage if you're running the pump off an engine instead of electric.
Bulk Fuel Storage Planner →Check wire sizing for the long run from the transformer to the pump panel at the wellhead.
Wire Sizing Calculator →Read the guide on friction loss, TDH, pump curves, NPSH, and source gaps for irrigation systems.
Irrigation Pump & Pipe Guide →How It Works
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Enter Flow Requirements
Input target flow rate (GPM) and select pipe material (PVC, aluminum, HDPE, steel new, steel aged) and pipe size.
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Enter System Details
Input total pipe length, elevation change, delivery pressure, suction head, and add any fittings (elbows, tees, valves) for equivalent length calculation.
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Review Planning Outputs
Review TDH, water HP, shaft HP, velocity calculator, and energy cost estimates, then compare pipe sizes before checking product data and pump curves.
Built For
- Farmers screening irrigation pump and pipe options
- Irrigation dealers preparing early planning conversations
- Well drillers framing TDH inputs before pump-curve review
- Farm managers comparing irrigation energy-cost sensitivity
Assumptions
- Hazen-Williams output is feet of head per 100 feet; PSI per 100 feet is derived separately by dividing by 2.31
- Pipe IDs, C-factors, and fitting equivalent lengths are local planning rows and must be checked against current product and site data
- Pump efficiency is user-entered and must be checked against the selected pump curve at the operating point
- Water is assumed; temperature, viscosity, suspended solids, entrained air, and laminar/transitional flow are not modeled
- Suction head is simplified and does not calculate NPSHa, vapor pressure, suction-side friction, priming, or submergence
- Energy cost assumes a constant electric rate and a fixed motor-efficiency planning value
Limitations
- Does not validate exact pipe standard, schedule, SDR, pressure class, inside diameter, wall thickness, couplings, or temperature derate
- Does not model pump curves, impeller trim, NPSHr, NPSHa, motor service factor, VFD behavior, or minimum flow
- Does not include all system losses such as filters, backflow devices, meters, emitters, nozzles, pressure regulators, or control valves
- Does not calculate lateral flow reduction, center-pivot package performance, or microirrigation emitter pressure compensation
- Does not model water hammer, surge pressure, air/vacuum relief, pressure relief, check-valve closing behavior, or transient analysis
- Does not verify well sustained yield, water rights, permits, chemigation safety, backflow rules, environmental controls, or electrical/AHJ requirements
- Hazen-Williams is empirical for water-service screening and may not be the accepted project basis where Darcy-Weisbach, manufacturer data, or measured testing is required
References
- USDA NRCS Part 652 Irrigation Guide source pointer for TDH worksheets, velocity notes, pump curve prompts, and horsepower context
- NDSU Extension AE1057 Irrigation Water Pumps source pointer for TDH, pressure-head conversion, suction head, pump horsepower, and NPSH context
- ASABE EP405.1 R2024 source pointer for microirrigation design and installation context
- ASTM D1785, ASTM F714, ASTM B241/B241M, and ASTM A53 source pointers for pipe-standard validation context
- Crane TP-410 source pointer for valve, fitting, pipe, and pump loss context
- USGS water-equivalent source pointer for acre-inch volume conversion
Frequently Asked Questions
Learn More
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