Free engineering calculators for common fluid-flow, pump, and heat-transfer calculations. Each tool shows the governing equation, assumptions, and intermediate values so the result can be checked.
Pipe Pressure DropStraight-pipe friction plus fitting losses with US customary and SI units.Pipe VelocityCalculate average velocity from volumetric flow rate and inside diameter.Reynolds NumberCalculate Reynolds number from dynamic or kinematic viscosity and identify the flow regime.Darcy Friction FactorCalculate Darcy and Fanning friction factors from Reynolds number and roughness.K Factor ↔ Equivalent LengthConvert a minor-loss coefficient to equivalent straight-pipe length, or back to K.Valve Cv for LiquidsSolve liquid valve Cv, flow rate, or pressure drop using the basic incompressible sizing relation.Pump PowerCalculate hydraulic and shaft power from flow, head or pressure rise, density, and efficiency.NPSH AvailableCalculate NPSH available from absolute pressure, vapor pressure, elevation, and suction losses.Liquid Orifice FlowEstimate incompressible liquid flow or differential pressure across an orifice plate from a supplied discharge coefficient.Multi-Layer Heat TransferBuild a series stack of solid layers, convection films, and contact resistances; solve heat flow, temperatures, conductivity, thickness, or h.