dBm/Hz to dBm/MHz Calculator

Use this calculator to convert peak amplitude measured in one resolution bandwidth to another.


The resolution bandwidth (RBW) setting is an important consideration when making spectrum analyzer measurements. Typically it is set to 10 kHz. This calculator helps you quickly convert from one RBW setting to another.

How to use the Calculator

  • Enter the peak amplitude of the signal and the associated bandwidth.
  • The default setting in the calc is -100 dBm in a 10 kHz bandwidth.
  • Set the desired bandwidth. The default setting is 1 MHz.
  • The tool will report the output peak amplitude in 1 MHz bandwidth.
  • In this case it works out to -80 dBm in 1 MHz RBW.


The displayed average noise level (DANL) of the Siglent Spectrum Analyzer is -161 dBm/Hz. If the RBW is changed to 10 MHz, the resulting noise level will be -91 dBm.