Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

Voltage Volts (V)

Required number input.

Impedance Ohms (Ω)

Required number input.

Ideal prospective short-circuit RMS current from source RMS voltage and total fault-loop impedance magnitude. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Current Amperes (A)

The resulting current amperes returned as a number.

• Electrical estimates require the correct AC or DC model, RMS and phase conventions, source impedance, grounding, conductor conditions, protection, temperature, harmonics, faults, and applicable standards. Nominal ratings are not automatically compatible design limits.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Short Circuit MVA

  Balanced three-phase fault apparent power in MVA from line-to-line voltage in kV and fault current in kA.

• Power Factor Correction Capacitor

  Ideal single-phase shunt capacitance needed to raise lagging power factor at fixed real power, RMS voltage and frequency.

• Battery Internal Resistance

  Apparent battery DC internal resistance from open-circuit and loaded terminal voltages at a measured discharge current.