dBm to Vrms Conversion Calculator

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Convert dBm to Vrms

Our tool is designed to help you effortlessly convert decibels-milliwatts (dBm) to volts root mean square (Vrms). Understanding and performing this conversion is essential in many fields, including telecommunications, audio engineering, and signal processing.

What is dBm?

dBm is a unit of power expressed in decibels relative to one milliwatt (mW). It is widely used in radio, microwave, and fiber optic communications to measure the absolute power levels of signals.

What is Vrms?

Vrms, or volts root mean square, is a measurement of the effective voltage of an alternating current (AC) signal. It represents the equivalent DC voltage that would deliver the same power to a load. Vrms is crucial in assessing the true power of AC signals, particularly in audio and electrical engineering.

How to Convert dBm to Vrms

The formula to convert dBm to Vrms is:

Vrms=Sqrt Z0×10^ ((dBm−30)/20)


  • is the power level in decibels-milliwatts.
  • Z0 is the impedance in ohms (Ω).
  • Vrms is the voltage in volts root mean square.


Applications of dBm to Vrms Conversion

Understanding how to convert dBm to Vrms is beneficial in various applications:

  • Telecommunications: Ensuring signal strength and quality in communication systems.
  • Audio Engineering: Measuring and controlling the power of audio signals.
  • Signal Processing: Analyzing and manipulating signal power in electronic devices.

Example Calculation

Let’s consider an example where you need to convert 1 dBm with an impedance of 50 ohms to Vrms:

Vrms=Sqrt 50×10^((1−30)/20)≈0.224 

This simple calculation shows how a small power level in dBm translates to an effective voltage in Vrms.