-3 dBm in watts (50Ω) = 501 µW
Worked conversion for -3 dBm into linear power and the equivalent RF voltage at a 50Ω impedance.
-3 dBm equals 501 µW -33 dBW · 158 mV RMS @ 50Ω
| Power level | -3 dBm |
| dBW (= dBm − 30) | -33 dBW |
| Power in milliwatts | 0.5012 mW |
| Power in watts | 0.0005012 W |
| Vrms @ 50Ω (sine) | 158 mV |
| Vpp @ 50Ω (sine) | 448 mV |
dBm is power referenced to 1 mW, so 0 dBm = 1 mW. Every +3 dB ≈ ×2 power and +10 dB = ×10 power. The voltage figures assume a sine wave dissipating this average power into a purely resistive 50Ω load.
Other levels or a different impedance? Convert any dBm / dBW / W / mW value in the interactive tool:
Open the dBm ↔ Watt Converter →Disclaimer: The Vrms / Vpp figures assume a single sine wave into a purely resistive 50Ω load. Real signals (modulated, multi-tone, reactive loads) will differ — use this as a reference estimate.