Convert dBm readings to watts and volts
A spectrum analyzer says −13 dBm — is that safe for the next stage? Convert it to mW and Vrms before you connect anything.
Tools used in this guide
The job
RF gear talks in dBm; power supplies and datasheets talk in watts and volts. The conversion depends on the load impedance — 50 Ω for most RF, 75 Ω for video.
One number in, three out
Enter any one of dBm, milliwatts or volts and read the other two. Set the load (50 Ω default) first — the voltage half of the answer changes with it.
- 0 dBm = 1 mW; every +10 dB multiplies power by 10.
- −13 dBm ≈ 0.05 mW ≈ 50 mVrms into 50 Ω — harmless for most inputs.
What it does not cover
This is pure power↔voltage across a resistive load. It says nothing about impedance matching, VSWR, or reactive loads — check those separately before connecting a real antenna or amplifier.