Pipe Velocity Calculator
Flow velocity and pipe sizing.
Enter your values
ⓘ Live results
Results
- Velocity
- 1.59 m/s
- Cross-sectional area
- 50.27 cm²
- Within limit?
- Yes
- Min diameter for limit
- 64 mm
Quick answer
Pipe velocity is flow rate divided by internal cross-sectional area.
v = Q ÷ A
How to use the Pipe Velocity Calculator
- 1Enter the design flow rate.
- 2Enter internal pipe diameter.
- 3Compare velocity against the recommended maximum.
Worked example
Using the values the calculator loads with:
Inputs
- Flow rate8 L/s
- Internal diameter80 mm
- Max recommended velocity2.5 m/s
Results
- Velocity1.59 m/s
- Cross-sectional area50.27 cm²
- Within limit?Yes
- Min diameter for limit64 mm
Frequently asked questions
What velocity is too high?
Above 2.5 m/s in water pipes causes noise and erosion.
Why does velocity matter?
Friction losses rise with the square of velocity.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.