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.

Distance

Required number input.

Frequency

Required number input.

Calculate free-space path loss in decibels for a link distance and frequency. 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]

Path loss

The resulting path loss returned as a number.

• Antenna formulas assume stated frequency, impedance match, polarization, efficiency, aperture, and propagation geometry. Nearby objects, ground, feed loss, multipath, regulatory averaging, near-field conditions, and pattern variation can make free-space or ideal-aperture results inaccurate.
• 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.

• Link Margin dB

  Compute the link margin in dB as EIRP plus receive gain minus free-space path loss minus receiver sensitivity.

• Link Budget Margin

  Compute the link margin in decibels as EIRP + receiver gain - path loss - receiver sensitivity.

• RFID Read Range

  Estimate free-space RFID forward-link range by the Friis equation from frequency, reader transmitted power, linear antenna gains, and tag activation power; reverse-link and regulatory limits are excluded.