Fluid Mechanics
Head ↔ Pressure Calculator
In fluid mechanics, the pressure exerted by a column of fluid is directly proportional to its height (head), density, and the local gravitational acceleration. This calculator converts between head and pressure for any fluid of known density.
TypeInteractive calculator — separate from unit conversions
Calculator
Default: water at ~20°C (editable)
m/s²
Standard gravity (editable)
Result
Pressure97.8704 kPa
Formulas
Pressure from head
P = ρ × g × h
Head from pressure
h = P / (ρ × g)
Diagram
Worked example
A water column is 10 m high. Density = 998 kg/m³, gravity = 9.80665 m/s². What is the pressure?
- 01P = ρ × g × h
- 02P = 998 × 9.80665 × 10
- 03P = 97,890.4 Pa
- 04P ≈ 97.89 kPa
Result
A 10 m column of water at 998 kg/m³ exerts approximately 97.89 kPa.
FAQ
Does this assume water density?
No. You must supply the fluid density. A default of 998 kg/m³ (water near 20°C) is shown for convenience, but it is clearly labelled and fully editable.
Is this a heat duty calculator?
No. This calculator only converts between head and pressure. Heat duty calculation is not implemented.
Can I change the gravity value?
Yes. The default is 9.80665 m/s² (standard gravity), but you can edit it for other locations or planetary bodies.
Does this handle gas columns?
Only if you provide a constant density. For compressible gases, the density varies with height and this simple formula does not apply.