How to Use the Pipe Sizing Calculator
✅ Select Your Measurement System
Choose between:
Imperial (feet, psi, gpm) – Common for local pipe standards.
Metric (meters, kPa, L/s) – Useful for projects requiring Canadian building code adherence.
✅ Choose Pipe Type
Select the appropriate material based on your irrigation needs:
PVC (Class 200, Schedule 40) – Standard for residential and commercial irrigation.
Polyethylene Drip Tubing – Ideal for drip systems and low-flow applications.
Copper Pipes – Occasionally used in high-end or specialized installations.
✅ Enter Desired Head Loss
Head loss refers to the pressure drop caused by pipe friction. Recommended values:
≤5 psi (Imperial) / ≤35 kPa (Metric) for efficient performance in varied elevations.
If unsure, enter a large number (e.g., 1000) to get an estimated pipe size and actual friction loss.
✅ Input Flow Rate
Flow rates depend on your system’s design and sprinkler specifications:
Residential: 8–12 gpm (Imperial) / 0.5–0.75 L/s (Metric).
✅ Enter Pipe Length
Use custom pipe lengths or input 100 to determine the typical head loss found in pipe charts.
✅ Calculate & Review Results
Ensure the selected pipe size meets recommended velocity limits:
≤5 fps (Imperial) / ≤1.5 m/s (Metric) to prevent excessive wear and inefficiencies.
Pipe Sizing Formula & Methodology
Hazen-Williams Equation
This widely used formula calculates friction loss based on:
Pipe material (C-value)
Diameter
Flow rate
Pipe length
Why Proper Pipe Sizing Matters
✅ Water Efficiency
Proper pipe sizing reduces water waste and ensures compliance with local conservation regulations.
✅ Pressure Consistency
Elevation changes affect water pressure and distribution. Correct pipe sizing helps balance pressure for even irrigation.
✅ Cost Savings
Oversized pipes increase material costs.
Undersized pipes cause inefficient water pressure and poor distribution.
Our calculator helps avoid these common mistakes, saving you money on materials and ensuring optimal performance.
Reliability
Our Pipe Sizing Calculator provides quick and reliable estimates, but for larger or more complex projects—especially those with elevation changes or low water pressure—it’s best to use manufacturer charts for the specific pipe you have or plan to purchase to ensure the most accurate results.