Convert RF power between dBm, watts, milliwatts and dBW. Enter a value in any unit and read the rest.
dBm is power in decibels relative to one milliwatt: dBm = 10 log(power in mW). dBW is relative to one watt, so dBW = dBm minus 30. Every 3 dB doubles the power, every 10 dB is ten times. 100 watts is 50 dBm or 20 dBW.
Watts = 10 to the power of ((dBm - 30) / 10). So 30 dBm is 1 watt, 60 dBm is 1000 watts. Going the other way, dBm = 10 log(watts) + 30.
dBW is power in decibels relative to one watt instead of one milliwatt, so it is simply dBm minus 30. 100 watts is 20 dBW or 50 dBm.
Decibels turn the huge range of RF power, from microwatts to kilowatts, into manageable numbers and turn gains and losses into simple addition. Every 3 dB is a doubling and every 10 dB is a tenfold change.