Pipe Size Calculator

Calculate the required internal pipe diameter for your heating system based on power, temperature difference, and target velocity.

Power (KW) 4.0

Temperature Difference (ΔT °C) 5

Target Velocity (v m/s) 0.9

Flow Rate

0.190

litres per second

Flow Rate

11.429

litres per minute

Internal Diameter

16.40

millimetres (mm)

Formula Reference

d = internal diameter (mm)
v = target velocity (m/s)
LPS = litres per second
LPM = litres per minute
KW = Kilowatts
SHC = Specific heat capacity (4.2)
ΔT = Delta T (°C)

Important: This calculator provides indicative pipe sizing guidance only. Always consult with a qualified heating engineer for your specific installation requirements.