This is more of a sticky note for myself than anything…I did a bunch of calculations and regressions based on my brewery setup and my refractometer, and established the following equation to convert from the specific gravity reading on my refractometer to a close approximation of specific gravity from my hydrometer:

h=1.070743072r-0.070823104
where h is the hydrometer reading (s.g.) and r is the refractometer reading (s.g.)

This equation seems to do a very good job of matching my previous values.

Note: I estimated a Brix correction factor of 1.0645 for my system.