Lately, several persons have posted about converting garages and spare rooms to control rooms, studios etc. The question about good room ratios has come up and links have been posted to Salford Univeristy’s page: Room Sizing Tutorial | Acoustics, Audio and Video | University of Salford That page is good but leaves a lot of slow and painful calculation when one considers all the alternatives.

I posted a crude excel sheet versus Salfords room ratios a week ago. I have improved the excel sheet since, so it is more versatile and easy to use. Several examples how to use it are included.

Feel free to use it.
If you pros find any errors in my examples, please point them out.
Edit: Cut down on some some (usually) unnecessary calculations.