Physics and Engineering

  • Water Vapor Pressure Calculator
    Calculate the saturation vapor pressure of water at any temperature using the Tetens formula. Get results in kPa, hPa (mbar), and mmHg.
  • Hoop Stress Calculator (Thin-Wall Pipe)
    Calculate hoop (circumferential) and axial stress in a thin-wall pressurized pipe or cylinder using σ = PD/2t. Enter pressure, diameter and wall thickness.
  • Pipe Wall Thickness Calculator (Barlow's Formula)
    Calculate minimum pipe wall thickness from internal pressure, outside diameter, and allowable stress using Barlow formula t = PD/(2S). In inches and mm.
  • Sprinkler Flow Rate Calculator
    Calculate fire sprinkler discharge flow rate (GPM) from K-factor and pressure using Q = K times the square root of P. Free hydraulic calculator.
  • GPM from Bucket Fill Time Calculator
    Calculate gallons per minute (GPM) flow rate from a bucket fill test. Enter container volume and fill time in seconds to get GPM and GPH.
  • Air Flow Rate (CFM) Calculator
    Calculate airflow in CFM from air velocity (ft/min) and rectangular duct dimensions. Uses CFM = velocity × duct area for HVAC sizing.
  • Pipe Water Velocity Calculator (GPM & Diameter)
    Calculate water velocity (ft/s) in a pipe from flow rate in GPM and inside diameter in inches. Fast, accurate plumbing and pipe-sizing tool.
  • Water Column to Pressure Calculator
    Convert a water column height (feet or inches of water) into pressure in PSI, kPa and bar. Uses ftH2O x 0.4335 and inH2O x 0.03613.
  • Volume Flow to Pipe Diameter Sizing Calculator
    Calculate the minimum pipe diameter from volume flow rate and target flow velocity using D = √(4Q/πv). Get diameter in mm and m plus pipe area.
  • Wind Load Pressure Calculator
    Calculate dynamic wind pressure with q = ½ρv². Enter wind speed and air density to get pressure in pascals, plus total wind force on an area.
  • Flow Rate to Velocity Converter
    Convert volumetric flow rate (Q) and pipe diameter into fluid velocity. Supports m³/s, L/s, GPM and mm, cm, in. Free pipe flow velocity calculator.
  • Darcy-Weisbach Pressure Drop Calculator
    Calculate pressure drop in a pipe using the Darcy-Weisbach equation from friction factor, length, diameter, density and velocity. Get Pa, kPa, bar and head loss.
  • Water Flow from Pipe Pressure & Diameter Calculator
    Estimate water flow rate from pipe pressure and inner diameter using Q = A·√(2P/ρ). Get results in L/min, m³/s, m³/h plus flow velocity.
  • Pump Power (HP) Calculator
    Calculate pump brake horsepower (BHP) and water horsepower from flow rate (GPM), total head (ft), specific gravity, and pump efficiency.
  • Mixing Two Fluids Final Temperature Calculator
    Calculate the final equilibrium temperature when two fluids are mixed, using mass, specific heat, and starting temperatures. Free physics tool.
  • Percent Efficiency Calculator
    Calculate percent efficiency from useful output and total input energy. Free online efficiency calculator using output/input × 100, with energy loss.
  • Valve Kv Flow Coefficient Calculator
    Calculate the valve flow coefficient Kv (metric) from flow rate, specific gravity and pressure drop. Get equivalent Cv too. Free engineering tool.
  • SCFM to ACFM Calculator
    Convert SCFM to ACFM using actual pressure and temperature. Free airflow conversion calculator for compressors, blowers, and HVAC systems.
  • Head Loss per 100 ft Calculator (Hazen-Williams)
    Calculate Hazen-Williams friction head loss in feet of water per 100 ft of pipe from flow rate (gpm), inside diameter, and C coefficient. US units.
  • Pipe Volume Capacity Calculator
    Calculate the water volume a pipe holds from its inside diameter and length. Results in liters, US gallons, cubic meters, and cubic feet.
  • Total Dynamic Head (TDH) Calculator
    Calculate Total Dynamic Head (TDH) for pump sizing by adding static head, friction head loss, and velocity head. Free, fast pump engineering tool.
  • Pump Hydraulic Power (kW) Calculator
    Calculate pump hydraulic power in kW from fluid density, gravity, flow rate and head using P = ρgQH. Also outputs watts, horsepower and shaft power.
  • Pump Brake Power & Efficiency Calculator
    Calculate pump brake (shaft) power from fluid density, flow rate, head and efficiency using P = ρgQH/η. Get kW and hp output instantly.
  • Pressure Drop from Flow Rate Calculator
    Calculate pipe pressure drop with the Darcy-Weisbach equation from friction factor, length, diameter, fluid density, and velocity. Get results in Pa, kPa, and bar.

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