Pitching rate dry yeast 100 gal batch

I just came into a 120 gal fermentor is 11 grams per 5 gal multiplied by 20 for a 100 gal batch proper pitch rate

Pitching rate is also dependent on starting gravity (and viability) in addition to volume.
Check out this pitching rate calculator: http://www.mrmalty.com/calc/calc.html