Enter the dBm, the impedance (ohms), and the resistance (ohms) into the calculator to determine the Current from dBm. 

Current from dBm Formula

The following formula is used to calculate the Current from dBm.

I = SQRT ( Z / 1000) * 10 ^ {(dBm / 20)} / R
  • Where I is the Current from dBm (amps)
  • Z is the dBm 
  • dBm is the impedance (ohms) 
  • R is the resistance (ohms) 

How to Calculate Current from dBm?

The following example problems outline how to calculate Current from dBm.

Example Problem #1

  1. First, determine the dBm. In this example, the dBm is determined to be 14 .
  2. Next, determine the impedance (ohms). For this problem, the impedance (ohms) is measured to be 5000 .
  3. Next, determine the resistance (ohms). In this case, the resistance (ohms) is found to be 60.
  4. Finally, calculate the Current from dBm using the formula above: 

I = SQRT ( Z / 1000) * 10 ^ (dBm) / 20 / R

Inserting the values from above and solving yields: 

I = SQRT ( 5000 / 1000) * 10 ^ (14 / 20) / 60 = .186 (amps)


Example Problem #2

Using the same method as above, determine the variables required by the formula. For this example problem, these are:

dBm = 42

impedance (ohms) = 10,000

resistance (ohms) = 5

Enter these given values into the calculator or above yields: 

I = SQRT ( Z / 1000) * 10 ^ (dBm) / 20 / R = 79.621 (amps)