The Pipe Velocity Calculator finds how fast water (or another fluid) is flowing inside a pipe, based on the flow rate and pipe diameter. Simply fill in the fields above and click Calculate to get an instant result.
This calculator is part of Calculate Wiki’s Construction Calculators collection.
What You’ll Need
- Flow Rate (GPM)
- Inside Diameter
Formula Used
Velocity = Flow rate (converted to ft³/s) ÷ Cross-sectional area
Example Calculation
Using example inputs — Flow Rate = 20 GPM; Diameter = 2 in — the Pipe Velocity Calculator returns:
| Value | Result |
|---|---|
| Cross-sectional area | 0.0218 ft² |
| Flow velocity | 2.04 ft/s |
2.04 ft/s.
Helpful Information
Results from the Pipe Velocity Calculator are estimates based on standard formulas used in the construction calculators field. Excessive velocity can cause pipe erosion or noise — consult local plumbing codes for recommended limits.
Frequently Asked Questions
Is the Pipe Velocity Calculator free to use?
Yes — the Pipe Velocity Calculator on Calculate Wiki is completely free, with no sign-up required.
How accurate is the Pipe Velocity Calculator?
The Pipe Velocity Calculator uses a standard, well-documented formula from the construction calculators field. Results are for informational purposes.
Can I use this on my phone?
Yes, this calculator is fully mobile-friendly and works on any modern browser.
What does the result mean?
For the example values shown above (20 GPM through a 2 in pipe), the flow velocity is 2.04 ft/s.