Pitot Tube Traverse Calculator
Average duct velocity and CFM from multiple pitot readings.
Enter your values
ⓘ Live results
Results
- Average velocity
- 1,853 FPM
- Airflow
- 5,559 CFM
- Number of points
- 6
- Average VP
- 0.215 in wc
Quick answer
Traverse velocity is found by averaging the square roots of each velocity pressure reading, then converting to velocity and multiplying by area.
V = 4005 x average(sqrt(VP_i)); CFM = V x Area
How to use the Pitot Tube Traverse Calculator
- 1Take pitot-tube velocity pressure readings at equal-area points across the duct (log-Tchebycheff or equal-area grid).
- 2Enter all readings comma-separated and the duct area.
- 3Read the average velocity and resulting CFM.
Worked example
Using the values the calculator loads with:
Inputs
- Velocity pressures (comma-separated)0.18, 0.22, 0.26, 0.24, 0.20, 0.19 in wc
- Duct area3.0 sq ft
Results
- Average velocity1,853 FPM
- Airflow5,559 CFM
- Number of points6
- Average VP0.215 in wc
Frequently asked questions
Why average square roots and not VP directly?
Velocity is proportional to the square root of VP, so averaging velocities (not pressures) gives the correct mean flow.
How many points are needed?
Typically 16-20 points for round ducts over 12 inches, fewer for smaller ducts.
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.