Orifice Flow Calculator

Find flow through an orifice under a head of fluid.

Flow rate (m³/s) 0.0039

Formula: Q = Cd·A·√(2·g·h)

Step-by-step with your numbers:
1. Values used:
2. Discharge coefficient = 0.62
3. Orifice area = 0.001
4. Head = 2
5. Gravity = 9.81 m/s²
6.
7. Flow rate = 0.0039m³/s
Did we solve your problem today?

Find the flow of liquid escaping through a small opening under gravity.

The math behind it

Q = Cd·A·√(2gh) (Torricelli's law with a discharge coefficient ~0.62 for a sharp orifice).

Worked example

Cd 0.62, A 0.001 m², head 2 m → about 0.00388 m³/s.

FAQ

Why √h?

Exit velocity is √(2gh), so flow scales with the square root of head.