dBm, Volts, Watts Conversion

dBm is defined as power ratio in decibel (dB) referenced to one milliwatt (mW). It is an abbreviation for dB with respect to 1 mW and the "m" in dBm stands for milliwatt.


Power level P(dBm) ref 1 mW
Voltage V(RMS)
Watt P(watts)
Impedance Z Ω

Here is an Excel spreadsheet containing the calculations:
dBm to Voltage to watts Microsoft Excel
and the conversion formulas here:
EMC Related Formulas Adobe Acrobat


dBm to watts conversion formula
dBm to volts conversion formula
watts to dBm conversion formula
volts to dBm conversion formula

View our other RF Conversion formula sheets:
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A.H. Systems, inc.
9710 Cozycroft Ave.
Chatsworth, CA 91311

P: (818) 998-0223

F: (818) 998-6892

E: Email

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