How to use the orifice discharge flow calculator
Find the flow rate through a small hole in a tank from the water head above it. Enter discharge coefficient, orifice diameter, head above orifice in the fields above; the discharge flow rate, discharge velocity are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “tank leak flow rate”, “orifice flow”, “hole in tank discharge”, “calculate orifice discharge flow”, “find discharge flow rate”.
Formula
Variables
- Cd — Discharge coefficient
- D — Orifice diameter (m)
- h — Head above orifice (m)
Worked example
With discharge coefficient = 0.6, orifice diameter = 0.02 m, head above orifice = 2 m, the calculator gives discharge flow rate ≈ 1.180569 L/s; discharge velocity ≈ 6.263114 m/s.
Frequently asked questions
What is the orifice discharge flow calculator used for?
Find the flow rate through a small hole in a tank from the water head above it. It helps with questions such as “tank leak flow rate”, “orifice flow”, “hole in tank discharge”.
What is the formula for the orifice discharge flow calculation?
Discharge flow rate (L/s) = Cd × π × (D / 2)^2 × √(2 × GRAV × h) × 1000. Discharge velocity (m/s) = √(2 × GRAV × h). Here Cd is discharge coefficient, D is orifice diameter (m), h is head above orifice (m).
What inputs do I need for the orifice discharge flow calculator?
You need discharge coefficient, orifice diameter in m, head above orifice in m. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the orifice discharge flow calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the orifice discharge flow result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.