I been using modular scales in my layouts and typesetting recently and have built a calculator to help produce double stranded scales.
I have also added in the calculations for ems and base 16 ems as I often need them when building websites.
Figures can be entered as straight numerals or in picas and points, as in 10p6 for 10 picas and 6 points.
Anyway I thought I'd share it here incase someone else may find it useful.
I would also appreciate any feedback or suggestions.