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 L dBm ref 1 mW
Voltage V V RMS
Watt W watts
Impedance Z Ω


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



View our other RF Conversion formula sheets:
Useful formulas for RF related conversions
Antenna Factor and Gain Calculations
Magnetic field convertions
Field Intensity Calculation
Antenna Beamwidth Coverage Calculations
Frequency and Wavelength Calculator
VSWR Calculations

Contact Details

A.H. Systems, inc.
9710 Cozycroft Ave.
Chatsworth, CA 91311

P: (818) 998-0223

F: (818) 998-6892

E: Email