Translation mW to dBm

Online converter translates mW to dBm. mW (mW) - milliwatt (that is 1/1000 watts) - unit of power measurement in general and radio signal power specifically. The value is absolute.
It can have values from 0 to very large figures.

dBm (dBm) - this is a decibel relative to "m", in this case relative to a milliwatt. In other words, it is a measure of how many decibels this power is greater (or less) than 1 mW.