dBm to dBµV Conversion Calculator

dBm
Ω

The dBm to dBµV Conversion Calculator converts a power level expressed in dBm (decibel-milliwatts) to an equivalent voltage level in dBµV (decibel-microvolts). This conversion is commonly used in RF, cable TV, and EMC measurements to relate signal power to voltage across a defined impedance.

Formula

dBµV = dBm + 90 + 20 × log10(√Z0)

Formula Explanation

  • dBm = Power level in decibel-milliwatts.
  • Z0 = Characteristic impedance of the system, typically 50 Ω or 75 Ω.
  • The term 90 adjusts for the conversion from milliwatts to microvolts, and the 20 × log10(√Z0) factor accounts for the voltage-to-power relationship at a given impedance.

Uses of this calculator

  • Converting measured power levels (dBm) to voltage levels (dBµV) for compliance testing.
  • Analyzing RF signals in communication and broadcast systems.
  • Evaluating performance of cable TV and EMC systems.
  • Cross-referencing dBm readings to dBµV for instrumentation and calibration.

What is 0 dBm in dBµV for a 50-ohm system?

Input: dBm = 0, Z0 = 50 Ω

Output:

  • dBµV = 0 + 90 + 20 × log10(√50)
  • dBµV = 90 + 20 × log10(7.071)
  • dBµV = 90 + 20 × 0.849 = 90 + 16.98 = 106.98 dBµV
  • 0 dBm equals approximately 107 dBµV in a 50 Ω system.