>>1460512I'd use this even if you burgers can't into metric it should give you a better idea.
At week 18 that's 1.35 lbs / week per chicken, and the chicken weighs about 3.3 lbs.
If it was eating 12lb per week this is 1.7 per day, so it would be eating half its body weight in feed every day. No animal that I know of does this lol