Pipe Velocity From Flow Rate

Calculate average velocity in a full circular pipe from volumetric flow rate and inside diameter.

Concept

Results

Enter inputs and select Calculate to display reviewed results.

Inputs

Volumetric flow rate *

Pipe inside diameter *

Formula & Variables

V =QAwhereA =πD_i²4

A: Area; [m^2]
D_i: Inside diameter; [m]
Q: Volumetric flow rate; [m^3/s]
V: Average velocity; [m/s]

Assumptions

Pipe is circular, full, and has a uniform inside diameter.
Flow rate is steady or time-averaged.
Velocity is cross-sectional average velocity.

⚠ Limitations

Partially full pipes, open channels, annular passages, and noncircular ducts require different area definitions.
No SCFM/ACFM or gas-state correction is performed.