mW-to-dBm / dBm-to-mW Power Conversion

Power is commonly expressed in decibel values in order to make adjustments due to loses and gains. The logarithmic nature of decibel units translates the multiplication and division associated with gains and losses into addition and subtraction. Once you get used to it, you will never want to return to watts. Units of dBm are decibels relative to 1 mW of power, hence, 0 dBm 1 mW. 1/100 mW is -20 dBm and 100 mW is +20 dBm. Powers less than 1 mW are always negative dBm values, and powers greater than 1 mW are always positive. See the graph below.

Here are the formulas:

P(mW) = 10^[P(dBm)/10]

P(dBm)=10*log[P(mW)]

RF Cafe - mW-to-dBm Power Conversion chart plot graph




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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ... All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged. My Hobby Website: AirplanesAndRockets.com