dBm per Hz (dBm/Hz) also called Power Spectral Density, is the amount of power in dBm per Hertz of bandwidth.

To convert dBm/Hz to dBm, enter the value and desired bandwidth in the calculator below.

The tool will calculate the power over this bandwidth and provide a value in both dBm and Watt.

## What is dBm/Hz used for?

dBm/Hz is the power of the signal measured in a 1 Hz resolution bandwidth. The measurement is normalized to 1 Hz.

This unit is often used to specify the sensitivity of a spectrum analyzer. Manufacturer’s call it the Displayed Average Noise Level (DANL).

The lower the DANL, the more sensitive the analyzer. The lowest noise floor that can be theoretically measured at 0^{o}C is **-174 dBm/Hz**. This assumes a noise figure of 0 dB.

As the Resolution Bandwidth (RBW) setting of the analyzer is increased, the DANL increases and this tool can be used to calculate that level.

**Notes**

[1] Use this calculator to convert between user-defined values of RBW. For instance to convert from -95 dBm at 1 kHz RBW to 100 MHz RBW.