As with all things drums are governed by an international standard, the subject drum being sized at 22.5 inch diameter and 33.25 height internally giving the following nominal volumes,
57.23 US Gals
47.66 Imp Gals
216.64 Litres
In Oz industry is referred to as a 44 Gal, 205 Litre, why 205 when 44 = 200?,