Hi Collin
I made up a simple calculator a while back using Excel.
I use it with my mill which has fixed feeds and speeds via gearing. If your mill is similar change the settings in the sheet to fit your machine then you will get a chart showing the available ranges for the particular cutter you are using.
The calculation is based on the amount of metal removed within the horsepower available and the size of the cutter.
settings outside the range are marked on the chart
The sheet is unprotected so you can adjust it to fit your parameters.
Link: Below:
**LINK**
Regards
John