Orifice Flow Rate Calculator

Inputs

Orifice diameter (d)

Actual orifice bore diameter.

Pressure drop (dp)

Pressure difference across the orifice.

bar

Discharge coefficient (Cd)

Accounts for contraction and losses. Sharp-edged liquid orifices are often near 0.60-0.65.

Fluid density (rho)

Density at operating temperature.

kg/m³

Default result

Orifice flow rate(Q)

41.36L/min

Q = Cd x A x sqrt(2dp/rho).

Also computed

Effective jet velocity(Cd*v_ideal)8.777m/s

Ideal velocity(sqrt(2dp/rho))14.16m/s

Orifice area(A)78.54mm²

Mass flow(m_dot)0.688kg/s

Method notes 2 notes

Liquid orifice flow uses Q = Cd*A*sqrt(2*dp/rho). Cd must match the orifice geometry and Reynolds-number range.
This incompressible screen is not for choked gas flow, two-phase flow, cavitating restrictions, control-valve sizing or calibrated custody-transfer metering.