Watts and dBm are units of measurement used to express the power of a signal in a telecommunications system.

Watts (W) is a unit of power that is commonly used to express the output power of radio transmitters and the power consumption of electrical devices. It is a unit of power that is defined as the amount of energy consumed or produced per second.

dBm (decibel-milliwatts) is a unit of measurement used to express the power level of a radio frequency (RF) signal in relation to one milliwatt (mW). It is an absolute unit of measurement that expresses the power level of a signal in decibels (dB) above or below one milliwatt.

The formula for converting watts to dBm is: dBm = 10 * log10 (power (in watts) / 1mW)

For example, if the power level of a signal is measured to be 50 watts, the power level in dBm can be calculated as: dBm = 10 * log10 (50 / 1) = 43.98 dBm

It’s important to note that dBm is an absolute unit of measure, while dB is a relative unit. It’s also important to note that dBm is only used in telecommunication, where as watts can be used in any field, including energy and electricity.

This formula is based on the fact that dBm is a logarithmic measure of power, relative to a reference power level of 1 milliwatt (mW). To convert from dBm to watts, you simply need to use the inverse logarithm, which is the power of 10.

For example, if you have a signal level of -20 dBm, you can calculate the equivalent power in watts by plugging that value into the formula:

Watts = 10 ((-20 – 30)/10) = 10 (-50/10) = 10 (-5) = 0.00001 = 0.1 mW

It’s worth noting that dBm is commonly used in radio frequency (RF) measurements, where it’s used to express the power level of a signal relative to 1 milliwatt. It’s a dimensionless unit and will not change with the system or the units.