tools / RF & SDR
dBm to Watt Converter
Type a power in any unit and the rest fall out live: dBm, milliwatts, watts, dBW and dBµV in a 50 ohm system. It is the conversion you keep needing when you read a datasheet or check a regional power limit like 14 dBm.
+10 dB = ×10 power · +3 dB ≈ ×2 power.
dBm14 dBm
Milliwatts25.12 mW
Watts0.0251 W
dBW-16 dBW
dBµV (50Ω)121 dBµV
How it works
How they relate
dBm is power referenced to 1 milliwatt: P(mW) = 10^(dBm/10), and dBm = 10·log10(P in mW). Watts are mW over 1000, dBW is dBm minus 30, and in a 50 ohm system dBµV is roughly dBm plus 107.
FAQ
What is 20 dBm in watts?
20 dBm is 100 mW, or 0.1 W. Every 10 dB is ten times the power, and 3 dB is about double.
What is the EU 868 MHz power limit?
Usually 14 dBm (25 mW) ERP for the general 868 band. Enter 14 dBm to see the milliwatts.
