14 free fluid mechanics calculators that run in your browser, with no sign-up and no download. Each one sits on the page that explains the concept and its formulas, and its results update as you type.

Pressure drop and pipes

Major head loss Pressure drop of a straight pipe by Darcy-Weisbach and Colebrook-White, for water, air, oils or any other fluid. ΔP in Pa, mbar and metres of head, Reynolds number, λ, ΔP versus flow curve Open the calculator → Minor losses Loss coefficient ζ and pressure drop of bends, valves, check valves, tees, expansions and contractions. ζ, ΔP, dynamic pressure, equivalent pipe length Open the calculator → Flow rate, velocity and diameter Continuity equation Q = V × A: enter two values, the third is calculated. Flow rate in m³/h, L/s and L/min, velocity, diameter, flow area Open the calculator → Pipe size selection The right pipe in a commercial series (steel, copper, PVC, HDPE, ducts) for the target pressure drop and velocity. Recommended pipe, velocity and pressure drop of each size Open the calculator → Reynolds number Re for a pipe, an aerofoil, a flat plate or a bluff body, with the matching flow regime. Re, flow regime, critical velocities, boundary layer and friction Open the calculator →

Pumps and valves

NPSH and cavitation Available NPSH of a pumping installation compared with the pump's required NPSH. Available NPSH, cavitation diagnosis, maximum suction lift Open the calculator → Pump operating point Intersection of the pump curve (6 points) and the system curve, with pumps in series or in parallel. Operating flow and head, power, chart Open the calculator → Kv, Cv and valve authority Pressure drop of a valve from its Kv or Cv, required Kv and authority over the controlled branch. ΔP, Kv, Cv, equivalent ζ, authority and standard Kvs values Open the calculator →

Aerodynamics and hydrodynamics

Drag of a body Drag force on a sphere, a cylinder, a plate, a parachute or any body of known drag coefficient. Drag in N and kgf, drag coefficient, Reynolds number, power Open the calculator → Lift and drag of a wing Lift and drag of a wing, a foil or a keel, including the induced drag due to aspect ratio. Lift, profile and induced drag, lift-to-drag ratio Open the calculator → NACA aerofoil generator Plot and coordinates of 4-digit and 5-digit NACA aerofoils, to download for Heliciel, SolidWorks or Excel. Plot, thickness, camber, zero-lift angle, .dat, .txt and .csv files Open the calculator →

Unit conversion

Pressure converter All pressure units, and gauge to absolute pressure according to altitude. Pa, bar, psi, mH₂O, mmHg… and absolute or gauge pressure Open the calculator → Viscosity converter Dynamic and kinematic viscosity, and oil units (SSU, Engler degrees). Pa·s, cP, cSt, St, SSU, °E Open the calculator → Nm³/h, m³/h and kg/h converter Gas flow rate at normal conditions (DIN 1343, ISO 2533), actual operating conditions and mass flow. Nm³/h, actual m³/h, kg/h Open the calculator →