Update April, 2013: Now supports Plato and SG for inputs and reports apparent attenuation, calories,
and the OG/FG in both sugar scales.
The calories equation is independent of the ABV equation, and is derived from
["Caloric Content, Beer-33" in: American Society of Brewing Chemists, 1992, Methods of Analysis of the ASBC. American Society of Brewing Chemists; Homebrew Digest 800-9],
complete details here:
http://hbd.org/ensmingr/.