# dBm - dBw Watts Conversion Table

### Decibel tutorial includes

The decibel is widely used in radio and electronics design calculations in particular it is used in many RF or radio frequency associated specifications and details.

When measuring radio frequency, or RF power, it is often easier to have a measurement made in a way that it is easy to compare the two levels.

As a result many power levels are specified in dBm or dBW, and much RF test equipment including power meters, spectrum analysers, signal generators and the like have calibrations in dBm or dBW. Often RF components such as mixers, oscillators and the like, as well as the interfaces between modules in RF equipment have their levels specified in dBm or dBW. Radio transmitters may also have their output levels expressed in this way.

## What are dBm and dBW?

In itself a decibel is not an absolute level. It is purely a comparison between two levels, and on its own it cannot be used to measure an absolute level. As a result of this the quantities of dBm and dBW are used:

• dBm - This is a power expressed in decibels relative to one milliwatt.
• dBW - This is a power expressed in decibels relative to one watt.

From this it can be seen that a level of 10 dBm is ten dB above one milliwatt, i.e. 10 mW. Similarly a power level of 20 dBW is 100 times that of one watt, i.e. 100 watts.

A more extensive conversion table of dBm, dBW and power is given below:

dBm dBW Watts Terminology
+100 +70 10 000 000         10 Megawatts
+90 +60 1 000 000         1 Megawatt
+80 +50 100 000         100 kilowatts
+70 +40 10 000         10 kilowatts
+60 +30 1 000         1 kilowatt
+50 +20 100         100 watts
+40 +10 10         10 watts
+30 0 1         1 watt
+20 -10 0.1         100 milliwatts
+10 -20 0.01         10 milliwatts
0 -30 0.001         1 milliwatt
-10 -40 0.0001         100 microwatts
-20 -50 0.00001         10 microwatts
-30 -60 0.000001         1 microwatt
-40 -70 0.0000001         100 nanowatts
-50 -80 0.00000001         10 nanowatts
-60 -90 0.000000001         1 nanowatt

The use of the values dBm and dBW is widespread. They are found as direct calibration scales on many items of RF test equipment often being used in preference to the more elementary basic units of watts or milliwatts. Items of RF test equipment including power meters, signal generators and RF spectrum analyzers in particular use these units. Accordingly to be able to understand the RF test equipment specifications it is necessary to have an understanding of dBm and dBW. Also many RF components are also specified in terms of dBm or dBW.

<< Previous   |   Next >>

### Other popular tutorials

Mark Patrick | Mouser Electronics
Refining IoT Technology to Address Demands of the Healthcare Market
The Internet of Things, IoT is destined to affect many areas of everyday life - we expect it will include many areas like smart meters, remote control of lighting, but what about the healthcare market . . .
Online - RF and Microwave Connector Types & Connector Care
Know your connector types and avoid expensive damage

More training courses

Using Digital Control Designs for Stable Power Supplies
Find out how to achieve stable power supply designs with fast transient response by using digital control techniques in this whitepaper from Intersil.

More whitepapers

##### Channels
Radio-Electronics.com is operated and owned by Adrio Communications Ltd and edited by Ian Poole. All information is © Adrio Communications Ltd and may not be copied except for individual personal use. This includes copying material in whatever form into website pages. While every effort is made to ensure the accuracy of the information on Radio-Electronics.com, no liability is accepted for any consequences of using it. This site uses cookies. By using this site, these terms including the use of cookies are accepted. More explanation can be found in our Privacy Policy