Fluid Mechanics Calculators

Last updated: September 2026

Pipe Flow Velocity Calculator

Calculates the average flow velocity of fluid in a circular pipe given a volumetric flow rate and pipe diameter.

Calculate water flow rate in pressurised pipes using the Hazen-Williams equation given pipe diameter, hydraulic gradient, and C factor.

Estimate the pressure head lost to friction in any pipe system using the Darcy-Weisbach equation.

Calculate the shaft power and motor input power needed to pump a fluid against a given head.

Estimate volumetric flow rate (discharge) over a weir structure given its width, head height, and discharge coefficient.

Calculate volumetric flow rate through an orifice plate or sharp-edged opening given pressure drop and fluid properties.

Calculates pressure drop along a pipe section using the Darcy-Weisbach equation.

Calculates the volumetric flow rate through an orifice plate or opening given the upstream-to-downstream pressure difference.

Estimate water flow velocity and discharge in a pressurized pipe using the empirical Hazen-Williams equation.

Find the Darcy-Weisbach friction factor for laminar or turbulent pipe flow from the Reynolds number and pipe roughness.

Distribute flow between two parallel pipes based on their diameters, lengths, and roughness using Hardy-Cross principles.

Compute the total mechanical energy per unit volume of a flowing fluid at a point by summing static pressure, kinetic pressure, and elevation head.

Calculate volumetric flow rate over rectangular, triangular, or trapezoidal weirs from the head of water above the weir crest.

Analyzes hydraulic jump characteristics in open channel flow, including sequent depth, energy loss, and jump length.

Calculate how long it takes to drain a tank from one liquid level to another through a bottom orifice.