dBm/Hz to dBm Calculator

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.

dBm to dBm/Hz

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 0oC 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.


[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.