Re: dough hydration?

Ive been making pies for many many years now.  I’ve made them at home and Ive made them at various pizza jobs. The whole percentage thing is new to me though. At the various shops it was always just use these ingredients in these measurements.  I’d like to recreate a dough from a previous shop I worked at. The measurements I remember was for 50 pounds of flour we used 12 quarts of water, 3 C whole milk ( I assume for browning?), 3 C oil blend, salt and sugar and a 1 # block of yeast.

What would be the hydration percentage? Does the percentage include all liquids or just water to flour ratio? Thank you if you can help.

Weight of 12 qt. water @ 2.085#/qt. = 25.02#
Weight of 3 US cup milk w/87% water @ 0. 87* 0.54#/cup = 0.87*1.62#=1.41# water
Total water = (25.02 + 1. 41)# = 26.42#

HR= weight of water/weight of flour
    =26.42#/50#
    = 0.5284 * 100 = 52.84%