Volts to dBm Calculator

Converting voltage (V) to dBm (decibels – milliwatts) is crucial in RF engineering, telecommunications, audio systems, and any domain where signal power is important.

Our dBm to Volts Calculator simplifies this conversion by using the appropriate formulas based on impedance, usually 50Ω.

What Is Voltage?

Voltage (V) is the electrical potential difference between two points in a circuit.

It represents how strongly electricity is being pushed through a conductor.

What is dBm?

dBm is a unit of power, not voltage.
It expresses power levels in decibels relative to 1 milliwatt (mW).

Volts to dBm Conversion Formula

To convert voltage (V) into power expressed in dBm, use the following steps:

Step 1: Convert Voltage to Power (in Watts)

$$P\left(W\right)=\frac{V^2}{R}$$

Where:

• $V$ = voltage in volts
• $R$ = impedance (Ω)

Step 2: Convert Watts to Milliwatts

$$P\left(\mathrm{mW}\right)=P\left(W\right)\times 1000$$ $$\text{dBm}=10\times {\log }_{10}\left(\frac{P\left(\text{mW}\right)}{1\text{mW}}\right)$$ $$\text{dBm}=10\times {\log }_{10}\left(\frac{V^2}{R\times 1\text{mW}}\right)$$

$$\text{dBm}=20{\log }_{10}\left(V\right)-10{\log }_{10}\left(R\right)+30$$

How to convert Volts to dBm using our calculator?

1. Enter the “Voltage” and “Impedance” values.
   (Impedance, however, is optional.)
2. Click “Calculate” to find dBm.