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.

Mutual Inductance (H) (H)

Required number input.

Primary Inductance (H) (H)

Required number input.

Secondary Inductance (H) (H)

Required number input.

Calculate dimensionless NFC coil coupling coefficient k=M/√(L1L2) from mutual and self-inductances measured under the same conditions. 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]

Coupling Coefficient

The resulting coupling coefficient returned as a number.

• NFC coupling depends on coil geometry, alignment, distance, ferrite, metal detuning, matching, Q, drive, load modulation, and regulatory field limits. A coupling coefficient alone does not establish reliable protocol operation.
• 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.

• Crosstalk Far End Voltage

  Estimate far-end crosstalk voltage from a measured or specified dimensionless far-end coupling coefficient and aggressor voltage; this is not a cable-geometry prediction.

• Crosstalk Near End Voltage

  Estimate near-end crosstalk voltage from a measured or specified dimensionless near-end coupling coefficient and aggressor voltage; this is not a cable-geometry prediction.

• Display Contrast Ratio

  On/off display contrast ratio from white and black luminance measured under the same conditions.