40 dBm in watts (50Ω) = 10.0 W
Worked conversion for 40 dBm into linear power and the equivalent RF voltage at a 50Ω impedance.
40 dBm equals 10.0 W 10 dBW · 22.4 V RMS @ 50Ω
| Power level | 40 dBm |
| dBW (= dBm − 30) | 10 dBW |
| Power in milliwatts | 1.000e+4 mW |
| Power in watts | 10.00 W |
| Vrms @ 50Ω (sine) | 22.4 V |
| Vpp @ 50Ω (sine) | 63.2 V |
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.