Pitot Tube Velocity Calculator
Enter stagnation (dynamic) pressure and fluid density to compute the flow velocity v = √(2·Δp/ρ).
Input Data
Results
At a glance:A Pitot tube measures fluid velocity by converting kinetic energy into pressure. Bernoulli's equation gives the dynamic pressure q = ½ρv² = p_stagnation − p_static. Solving for velocity: v = √(2·Δp/ρ), where Δp is the measured stagnation-static pressure difference and ρ the fluid density. This is the basis of aircraft airspeed indicators and many flow meters. For compressible (high-Mach) flow a compressibility correction is needed; the incompressible form above is accurate for M ≲ 0.3. This tool computes v from Δp and ρ.
Formula
v = √(2·Δp/ρ)
Dynamic pressure: q = ½·ρ·v²
$$v = \sqrt{\dfrac{2\,\Delta p}{\rho}}$$How to Use
- Enter the measured dynamic (stagnation-static) pressure Δp (Pa).
- Enter the fluid density ρ (kg/m³).
- The calculator returns the velocity v.
Case Studies
Airspeed
Δp = 600 Pa, ρ = 1.2 kg/m³ (air).
v = √(2×600/1.2) = √1000 ≈ 31.6 m/s.
≈ 114 km/h indicated airspeed.
FAQ
What does the Pitot tube actually measure?
The pressure difference between a forward-facing (stagnation) port and a side (static) port; this Δp equals the dynamic pressure ½ρv².
When is the formula inaccurate?
At high Mach number (M > 0.3) compressibility matters; use the compressible Bernoulli/isentropic relation instead.
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References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.