We had to wiggle around with ours for a bit. I set an amount, tried to stick with it & realized an unreasonable amount of my time was being spent looking for deals and going to various stores & still I wasn't getting under it & I was unhappy with the food choices. So I set it higher & took some from the entertainment budget. Turns out we don't spend that much on entertainment anyway
It's about $400 a month now for 2 adults & 2 kids. That's average over the course of a year. Some months it will be under $300 and others it will be over $500 if we do a bulk meat purchase chickens, pig or cow, with some friends. I keep an eye on sales at various stores. I do a 12 meal plan every 2 weeks & arrange shopping for ingredients by where they are cheapest. I'm hopeless with coupons so I just keep track of sales fliers.