Pipe Size Calculator

Calculate pipe diameter from flow rate and velocity with friction loss consideration — free plumbing design tool

Related Categories:Building Services

Input Conditions

Flow Rate Q (L/min)

Fluid

Max Velocity (m/s)

Pipe Material

Results

Required Inner Diameter	20.6 mm
Selected Pipe Size	20A (27.2 mm)
Inner Diameter	21.6 mm
Actual Velocity	1.36 m/s
Friction Loss	209.83 mmAq/m
Friction Loss (Pa/m)	2058.4 Pa/m

Standard Pipe Sizes

Nominal	OD (mm)	ID (mm)
15A	21.7	16.1
20A	27.2	21.6
25A	34	27.6
32A	42.7	35.7
40A	48.6	41.6
50A	60.5	52.9
65A	76.3	67.9
80A	89.1	80.7
100A	114.3	105.3
125A	139.8	130.8
150A	165.2	155.2