Calculator · Fluid Mechanics
Pitot Tube Calculator
A Pitot tube brings the flow to rest at its tip. The difference between that stagnation pressure and the local static pressure is the dynamic pressure, and for steady incompressible flow it gives the speed magnitude at the probe — no direction and, by itself, no flow rate.
Inputs
Use the density of the flowing fluid, not of the manometer liquid.
Results
Speed magnitude V = √(2Δp/ρ)
A magnitude at the probe tip. The direction of the flow is not measured by this reading.
| Differential Δp = p0 − p | 5 kPa |
|---|---|
| Fluid density ρ | 1000 kg/m³ |
| Speed magnitude V | 3.1623 m/s |
| Dynamic pressure ½ρV² | 5 kPa |
Assumptions
- · Steady, incompressible, frictionless flow along the stagnation streamline.
Explore in the Lab
A Pitot reading gives a local speed; a flow rate needs an area and a velocity profile assumption.
Technical reference
p0 − p = ½ ρ V²
V = sqrt(2Δp / ρ)
- p0
- stagnation (total) pressure at the tip[Pa]
- p
- local static pressure[Pa]
- V
- local speed magnitude[m/s]
- ρ
- density of the flowing fluid[kg/m³]
Steady, incompressible, frictionless flow along the stagnation streamline. Compressible and high-speed corrections are outside this version.
A zero differential is a valid reading and gives exactly zero speed.
Reference case: Δp = 5000 Pa in water at 1000 kg/m³ gives V ≈ 3.162277660 m/s.