Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Characteristic Impedance (Ω) (Ω)

Required number input.

Load Impedance (Ω) (Ω)

Required number input.

Calculate signed voltage reflection coefficient at a PCB transmission-line load as (Zload−Z0)/(Zload+Z0) for real positive impedances. 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]

Reflection Coefficient

The resulting reflection coefficient returned as a number.

• PCB trace calculations depend on finished copper thickness, geometry, dielectric stack-up, temperature rise criterion, ambient, neighboring conductors, return path, frequency, surface finish, and fabrication tolerance. IPC equations are approximations, not a substitute for the board fabricator's stack-up or field solving.
• 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 the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Motor Power Factor At Load

  Calculate balanced three-phase motor power factor as real input power divided by √3 times line voltage and line current; the result is a magnitude.

• Reflection Coefficient

  Compute the voltage reflection coefficient at the junction of a source and load impedance.

• Ac Motor Reactive Power

  Calculate positive reactive-power magnitude for a balanced three-phase motor from line voltage, line current, and power factor.