Orifice Flow Calculator
Calculate Q = Cd A √(2 ΔP / ρ) for incompressible flow.
How to Use This Calculator
1
Enter Cd and D
Use a discharge coefficient appropriate for your orifice geometry and Reynolds number.
2
Enter ρ and ΔP
Provide fluid density and pressure drop across the orifice.
3
Calculate flow
Press Calculate to get volumetric flow and jet velocity.
Formula
Q = Cd · A · √(2 ΔP / ρ)
Where: Q is flow (m³/s), Cd discharge coefficient, A area (m²), ΔP pressure drop (Pa), ρ density (kg/m³).
Example: Cd=0.62, D=0.05 m, ρ=1000 kg/m³, ΔP=50 kPa ⇒ Q ≈ 0.012 m³/s.
Frequently Asked Questions
How do I pick Cd?
Typical sharp-edged orifices use 0.60–0.65. Use vendor data or standards for your geometry and Re.
Compressible flow?
This formula assumes incompressible flow. For gases at large ΔP, use compressible or choked-flow relations.
Units?
Inputs are SI. Convert as needed to maintain consistency.