dBm <-> mW Calculator

dBm (sometimes dBmW or decibel-milliwatts) is unit of level used to indicate that a power ratio is expressed in decibels (dB) with reference to one milliwatt (mW). It is used in radio, microwave and fiber-optical communication networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form compared to dBW, which is referenced to one watt (1,000 mW).

The milliwatt (mW) is equal to one thousandth (10−3) of a watt. A typical laser pointer outputs about five milliwatts of light power, whereas a typical hearing aid for people uses less than one milliwatt. Audio signals and other electronic signal levels are often measured in dBm, referenced to one milliwatt.

How to convert dBm to mW:
The power conversion of dBm to mW is given by the formula:
P_(mW) = 1mW * 10^{(P_(dBm)/ 10)}

How to convert mW to dBm:
The power P(dBm) in dBm is equal to 10 times the base 10 logarithm of the power P(mW) in milliwatts (mW) divided by 1 milliwatt (mW):
P_(dBm) = 10 * log₁₀(P(mW) / 1mW)