Enter the total microvolts (uV) and the impedance of the system into the calculator to determine the DBM.

UV to DBM Formula

The following formula is used to calculate the DBM from UV. 

dBm = 20 * log_{10} (uV) - 10 * log_{10} (Z) -90
  • Where dBm is the decibel-milliwatts
  • uV is the micro volts
  • Z is the impedance (ohms)

To calculate dBm from uV, take the log base 10 of the uV and multiply by 20. Next, take the log base 10 of the impedance and multiply by 10. Subtract the second result from the first result, then subtract 90 again.

What is dBm?

Definition:

dBm, sometimes referred to as dBmw, is a unit of measure that describes the ratio of power in relation to one watt.

How to convert uV to dBM?

Example Problem:

The following example problem outlines the steps required to calculate dBm from uV.

First, determine the total amount of microvolts. In this example, the uV has a value of 10,000.

Next, determine the impedance of the system in ohms. For this case, the impedance is measured to be 50 ohms. This is the is a fairly standard amount of impedance for a system.

Finally, calculate the decibel-milliwatts using the formula above:

dBm = 20 * log10 (uV) – 10 * log 10 (Z) -90

dBm = 20 * log10 (10000) – 10 * log 10 (50) -90

dBm = -519