Pipe size calculator
Choose a pipe diameter from the flow it must carry and the maximum water velocity.
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How it is calculated
D = √(4 × Q / (π × v))
From the minimum diameter, pick the standard pipe whose internal diameter is equal or larger. For PE100, wall thickness is the outside diameter divided by the SDR.
Frequently asked questions
What pipe size for 44 GPM (10 m³/h)?
At 1.5 m/s the minimum internal diameter is 48.6 mm: a 63 mm PE100 SDR 17 pipe, or 2 in nominal schedule 40.
What does SDR mean?
Standard dimension ratio: outside diameter divided by wall thickness. A lower SDR means a thicker wall and higher pressure rating.