CR RF Calculator

We’ve created an intelligent calculator for estimating RF levels for basic coax applications. You’ll need Excel 2010 or higher to use the form – older versions can’t support the advanced data features.

We suggest you experiment with the app, and feel free to email questions to Doug Engstrom. Here’s the basic concept:

  • Select the channel bandwidth from a pull-down list
  • Enter the expected RF level for the site, usually 30 or 45 dBmV
  • Select the first component, either a splitter or tap. The value of a tap is rated for the dB level it subtracts at each output.
  • Add the length of coax that is home run to the next TV or component
  • If there is another splitter or tap at the end, the form shows the value of each output
  • If there are long coax runs from the component, enter the longest run you expect. That will give you the worst-case RF level for that run – the rest of the runs will have a higher level.
  • There are additional components to the right you can use to expand the system


  • RF Design Calc41014 – spreadsheet
  • RFCalc Sample 1 – basic design that uses a tap for short-medium RF feeds, splitter at the end to feed four long runs
  • RF Calc Sample 2– small system that uses all splitters – one 4-way to feed remote areas, 4- and 8-way splitters at the ends