# Dbm definition

A unit of measure used to reference signal strength to electrical power level. Unlike dB, which is a relative measure, dBm is an absolute measure, and can be used to express very small values (dBm) and very large values (dBW). The baseline reference relationship is 1mW = 0 dBm. A doubling of signal power yields an increase of approximately 3 dBm (2mW = 3 dBm) and halving of signal power yields a loss of approximately 3 dBm (500
(DeciBels at 1 Milliwatt) A measurement of power using one milliwatt as the reference point (0 dBm). For example, a signal at .1 milliwatt (100 microwatts) is a loss of 10 dBm. A radio station transmitting 50,000 watts of power may wind up attenuating to only a couple milliwatts by the time it is picked up by a radio receiver. See deciBel and dBA.dBm TO WATTS CONVERSIONWatts +40 dBm = 10 watts 10.0 +30 dBm = 1 watt 1.0 +20 dBm = 100 milliwatts .1 +10 dBm = 10 milliwatts .01 0 dBm = 1 milliwatt .001 -10 dBm = 100 microwatts .0001 -20 dBm = 10 microwatts .00001 -30 dBm = 1 microwatt .000001 -40 dBm = 100 nanowatts .0000001