Pipe Velocity Calculator with Flow Data & Charts

Calculate fluid flow velocity in circular pipes using Imperial and SI units. Supports calculations with volume flow rates and pipe inside diameters.

Pipe Velocity Calculator with Flow Data & Charts

Imperial Units

Fluid flow velocity in a circular pipe can be calculated as:

v = 0.4084 × q_gpm / d_in²

Where:

  • v = velocity (ft/s)
  • q_gpm = volume flow (US gal/min)
  • d_in = pipe inside diameter (inches)

SI Units

v = 1.273 × q / d²

Where:

  • v = velocity (m/s)
  • q = volume flow (m³/s)
  • d = pipe inside diameter (m)
Calculator

Inputs

Results

Flow Velocity-- ft/s
Calculator

Inputs

Results

Flow Velocity-- m/s
Pipe ScheduleNominal Size (in)Inside Diameter (in)Flow Rate (gpm)Velocity (ft/s)
Schedule 4022.067308.89
Schedule 4033.068608.14
Schedule 4044.0261009.78
Schedule 8021.939207.09
Schedule 8032.900508.62
Schedule 8043.826808.63