Venturi Meter Flow

Find the flow rate through a pipe from the pressure drop across a Venturi meter, free online.

Pipe diameter (mm)

Throat diameter (mm)

Pressure difference ΔP (kPa)

Fluid density (kg/m³)

Discharge coefficient

About this calculator

Q = C_d · A₂ · √(2ΔP ÷ (ρ(1 − β⁴))), where β = d₂ ÷ d₁ is the throat-to-pipe diameter ratio and C_d is the discharge coefficient (about 0.98 for a classical Venturi). The velocity rises in the throat as pressure falls (Bernoulli).