Recommended 0.2–0.75 for accuracy

Orifice, Venturi & Nozzle Calculator

Calculate flow rate Q, differential pressure ΔP and discharge coefficient for orifice plates, venturi meters and flow nozzles. ISO 5167 compliant for liquids and gases.

Flow Rate Q

85 m³/h

Orifice β=0.6, ΔP=10 kPa

Differential Pressure Flow Meters

Featured: Orifice • Venturi • Nozzle • ISO 5167

Meter Type

Calculation Mode

Pipe Diameter D (mm)

Beta Ratio β = d/D

Fluid Density ρ (kg/m³)

Flow Rate Q (m³/h)

Differential Pressure ΔP (kPa)

Expansibility Factor ε (Gas) ≈1 for liquids, <1 for gases

Cd vs Beta Ratio

Typical discharge coefficients

ISO 5167 Equation

Q = Cd × ε × (π/4) d² × √(2 ΔP / ρ (1-β⁴))
ΔP = (Q / (Cd ε (π/4) d²))² × ρ (1-β⁴) / 2

Enter parameters to calculate flow

DP Flow Meter Guidelines

Discharge Coefficient Cd

Orifice: 0.60–0.65

Venturi: 0.95–0.99

Nozzle: 0.95–0.98

Pressure Loss

Orifice: High (50–90% ΔP)

Venturi: Low (10–20% ΔP)

Nozzle: Medium