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Engineering ToolBox > Dynamic Pressure

Dynamic pressure is the component of fluid pressure that represents a fluids kinetic energy

The dynamic pressure is a defined property of a moving flow of gas or liquid and can be expressed as

p_d = 1/2 ρ v² (1)

where

p_d = dynamic pressure (Pa)

ρ = density of fluid (kg/m³)

v = velocity (m/s)

Dynamic Pressure Calculator

The calculator below can be used to calculate the dynamic pressure generated by a moving fluid. The calculator is generic and both SI and Imperial units can be used.

The default values below are for water with density of 1000 kg/m³.

ρ - density of fluid (kg/m³, lb_m/ft³)

v - velocity (m/s, ft/s)

SI-units Imperial units

Some common densities at atmospheric pressure:

• Water at 0^oC - 1000 kg/m³
• Water at 32^oF - 62.4 lb_m/ft³
• Air at 20^oC - 1.2 kg/m³
• Air at 59^oF - 0.0765 lb_m/ft³

Example - Dynamic Viscosity in a Water Flow

The dynamic pressure of water at 20^oC, 1000 kg/m³, flowing with velocity 5 m/s, can be calculated using (1) like

 p_d = 1/2 1000 kg/m³ (5 m/s)²

    = 12.5 kPa