Pressure & Flow Calculators
Bernoulli Equation Pressure Calculator
Calculate downstream pressure from upstream pressure and velocity change using Bernoulli's equation.
Choked Flow Critical Pressure Ratio Calculator
Calculate the critical pressure ratio for choked compressible flow from a gas's specific heat ratio.
Darcy-Weisbach Friction Loss Calculator
Calculate pipe friction pressure loss using the Darcy-Weisbach equation from friction factor, pipe geometry, and flow velocity.
Differential Pressure Calculator
Calculate the differential pressure produced by a flow measurement device for a given flow rate and meter K-factor.
Flow Discharge Coefficient Calculator
Calculate a flow device's discharge coefficient by comparing actual flow rate to theoretical flow rate.
Gas Flow Calculator
Calculate volumetric gas flow rate through a duct or pipe from average velocity and cross-sectional area.
Gas Velocity from Mass Flow Calculator
Calculate gas flow velocity from mass flow rate, gas density, and duct cross-sectional area.
Hydrostatic Pressure Calculator
Calculate hydrostatic pressure from fluid density and column height using the standard hydrostatic pressure formula.
Isentropic Stagnation Pressure Calculator
Calculate stagnation (total) pressure from static pressure, Mach number, and specific heat ratio using the isentropic flow relation.
Mach Number Calculator (Combustion Gas)
Calculate the Mach number of combustion gas flow from velocity, gas properties, and temperature.
Mass Flow Rate Calculator
Calculate mass flow rate of a gas from its density and volumetric flow rate.
Nozzle Thrust Calculator
Calculate total nozzle thrust from exhaust mass flow, exit velocity, and the pressure thrust term.
Orifice Flow Calculator
Calculate volumetric flow rate through a sharp-edged orifice from pressure drop, orifice area, and discharge coefficient.
Pipe Flow Hydraulic Power Calculator
Calculate ideal hydraulic power for pumping fluid from flow rate and pressure rise.
Pipe Velocity Calculator
Calculate average gas velocity inside a pipe or duct from volumetric flow rate and cross-sectional area.
Pitot Tube Velocity Calculator
Calculate flow velocity from Pitot tube stagnation-static pressure difference and fluid density.
Pressure Drop Calculator
Calculate frictional pressure drop of gas flowing through a duct or pipe using the Darcy-Weisbach equation.
Reynolds Number Calculator
Calculate the Reynolds number of combustion gas flow to determine laminar, transitional, or turbulent flow regime.
Venturi Meter Flow Rate Calculator
Calculate flow rate through a venturi meter from throat and pipe areas, pressure difference, and fluid density.
Volumetric Flow Rate Calculator
Calculate the volumetric flow rate of a gas from its mass flow rate and density.
Predicting How a Fluid Will Actually Behave
Whether flow through a pipe stays smooth (laminar) or becomes chaotic (turbulent) is not a guess — it is predicted by a single dimensionless number that engineers check before designing any flow system. These nine calculators cover pressure and flow math for gases and liquids.
Where Flow Crosses From Laminar to Turbulent
This single number, the Reynolds number, combines velocity, pipe diameter, and fluid viscosity into one value that predicts flow behavior more reliably than any of those factors alone — which is why it is checked before sizing a system, not after something behaves unexpectedly. Calculate it with the Reynolds Number Calculator.
Popular Pressure & Flow Calculators
- Pressure Drop Calculator — estimates pressure loss along a pipe or duct run from flow rate and geometry.
- Mass Flow Rate Calculator — converts volumetric flow into mass flow using fluid density.
- Orifice Flow Calculator — calculates flow rate through a restriction from pressure differential.
Related: Plumbing Calculators, Advanced Combustion Calculators for combustion-specific flow.