Engineering calculators

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• HVAC cooling loadMechanical

  Rough sensible cooling load for a space.

• Beam sizing (simply supported, UDL)Civil

  Max moment and required section modulus for a simply supported beam under a uniform load.

• Cable sizing & voltage dropElectrical

  Voltage drop for a copper/aluminium run at a given current and cross-section.

• Pump total headMechanical

  Total dynamic head = static lift + friction loss (Hazen-Williams).

• Ohm's law (V, I, R, P)Electrical

  Resistance and power from voltage and current.

• Three-phase powerElectrical

  Real and apparent power for a balanced 3-phase load.

• Transformer / kVA to ampsElectrical

  Full-load current from a kVA rating and voltage.

• Power factor correctionElectrical

  Capacitor kVAR needed to raise power factor.

• Electricity bill estimatorElectrical

  Monthly running cost of an appliance.

• Power converter (kW · HP · BTU/h)Mechanical

  Convert kilowatts to horsepower and BTU per hour.

• Steel plate weightMechanical

  Weight of a rectangular steel plate.

• Reynolds numberMechanical

  Reynolds number for pipe flow (laminar < 2300 < turbulent).

• Pipe flow velocityMechanical

  Fluid velocity from volumetric flow and pipe diameter.

• Bolt tightening torqueMechanical

  Approximate torque for a target bolt preload.

• V-belt lengthMechanical

  Approximate open-belt length for two pulleys.

• Concrete volume & mixCivil

  Concrete volume for a slab plus nominal-mix material quantities.

• Rebar weightCivil

  Total weight of steel reinforcement bars.

• Brick quantityCivil

  Approximate number of bricks in a wall.

• Temperature converter (°C → °F, K)General

  Convert Celsius to Fahrenheit and Kelvin.

• Pressure converter (bar → psi, kPa)General

  Convert bar to psi and kilopascal.