Decibel watt

Definition
The decibel watt (dBW) is a unit for the measurement of the strength of a signal expressed in decibels relative to one watt.

Overview
It is used because of its capability to express both very large and very small values of power in a short range of number; e.g., 1 milliwatt = −30 dBW, 1 watt = 0 dBW, 10 watts = 10 dBW, 100 watts = 20 dBW, and 1,000,000 W = 60 dBW.