Air Pressure at Altitude Calculator
Calculate atmospheric pressure, temperature, and air density at any altitude using the International Standard Atmosphere (ISA) model. Supports humidity correction.
Free Fluid Mechanics Calculators
22 toolsPressure, flow rate, buoyancy, viscosity, and hydraulic calculators. Browse our free fluid mechanics tools below — no sign-up required.
BMEP Calculator (Brake Mean Effective Pressure)
Calculate brake mean effective pressure from power, displacement, and RPM. Compare engine efficiency across sizes. Supports kW, hp, 2-stroke and 4-stroke.
Cv Flow Calculator
Calculate liquid flow rate, required Cv, or pressure drop using Q = Cv√(ΔP/SG). Quick Cv sizing for valves, fittings, and regulators.
Darcy–Weisbach Calculator
Calculate pipe friction head loss and pressure drop with the Darcy–Weisbach equation. Uses the Colebrook–White equation for turbulent friction factor.
Darcy's Law Calculator
Calculate groundwater flow using Darcy's law Q = KiA. Compute Darcy velocity, seepage velocity, travel time, and total flow for any soil type.
Differential Pressure Calculator
Calculate flow rate from differential pressure across orifice plates, Venturi tubes, flow nozzles, and Pitot tubes. Converts ΔP to flow velocity and volume.
Hydraulic Conductivity Calculator
Calculate hydraulic conductivity K, Darcy velocity, seepage velocity, and total flow for soils and aquifers. Presets for gravel through clay.
Hydraulic Gradient Calculator
Calculate hydraulic gradient i = Δh/L from head drop and flow path length. Supports elevation + pressure mode, slope-angle conversion, and scenario presets.
Hydraulic Jump Calculator
Calculate downstream depth, energy loss, jump length, and power dissipated in a hydraulic jump. Supports rectangular, trapezoidal, and triangular channels.
Hydraulic Pressure Calculator
Calculate hydraulic cylinder force, speed, and power from pressure, bore, rod, and flow rate. Supports extend and retract calculations.
Hydraulic Radius Calculator
Calculate hydraulic radius Rh = A/P and hydraulic diameter Dh = 4A/P for circular, rectangular, trapezoidal, and triangular cross-sections.
Hydrostatic Pressure Calculator
Calculate pressure at depth P = P₀ + ρgh for any liquid. Converts to kPa, atm, psi, bar, and mmHg with force on surfaces.
Isentropic Flow Calculator
Calculate isentropic flow relations: T/T₀, P/P₀, ρ/ρ₀, A/A*, velocity, and normal-shock properties for any Mach number and gas.
Kinematic Viscosity of Air Calculator
Calculate kinematic viscosity ν, dynamic viscosity μ, and density of air at any temperature and pressure using Sutherland's law.
Manometer Calculator
Calculate pressure from manometer height difference for U-tube, differential, inclined, and well-type manometers with multiple manometer fluids.
Open Channel Flow Calculator (Manning)
Calculate flow rate, velocity, and Froude number in open channels using Manning's equation. Supports rectangular, trapezoidal, triangular, and circular shapes.
Orifice Flow Calculator
Calculate flow rate through an orifice using Q = CdA√(2gh). Supports sharp-edged, beveled, and rounded orifice types with multiple fluids.
Pipe Flow Calculator
Calculate velocity, Reynolds number, friction factor, head loss, and pressure drop for pipe flow. Includes elevation change and pumping power.
Radiation Pressure Calculator
Calculate radiation pressure, force, and acceleration from electromagnetic radiation on absorbing or reflecting surfaces. Solar sail and laser propulsion analysis.
Reynolds Number Calculator
Calculate the Reynolds number Re = ρVD/μ to classify pipe or external flow as laminar, transitional, or turbulent. Includes friction factor and entrance length.
Valve Flow Coefficient (Cv / Kv) Calculator
Calculate valve Cv, flow rate, or pressure drop for control valves. Convert between Cv (US) and Kv (metric) with specific-gravity correction.
Water Viscosity Calculator
Calculate dynamic viscosity, kinematic viscosity, density, and thermal properties of water at any temperature from 0–100 °C.