Pressure Drop Calculator

Pressure drop is the loss of mechanical pressure as fluid moves through a passage, fitting, valve, or other resistance. Darcy-Weisbach major loss depends on friction factor, length-to-diameter ratio, density, and velocity, while minor losses use dimensionless K coefficients for local disturbances.

Pressure Drop Calculator applies this concept to its defined inputs and workflow. It separates major frictional loss from optional minor-loss K values and reports head loss. Its governing relationship or workflow is stated as follows: Pressure drop is the sum of major Darcy-Weisbach loss and optional minor-loss coefficient.

The calculator evaluates Geometry mode, Flow input mode, Viscosity mode, and Number format and returns Pressure Drop, base-unit normalization, formula substitution, and calculation steps using the stated method. The selected units and sign or reference conventions must describe one consistent physical case. Users should interpret the output within the assumptions shown on the page and repeat the check with trusted reference values when the result affects engineering or research decisions. Elevation, pumps, turbines, cavitation, phase change, and transient effects are not included.