We average around $900-1100/month. But it's hard to say exactly, b/c I do buy beer and wine sometimes, and things like dog food and prescriptions also come out of the same "pot" of money (I buy our prescriptions at the grocery or Target pharmacy). I have a child who is on regular prescriptions and OTC meds (asthma and allergies), so that can run $150-200 every few months when it's time to refill. I also have a spouse who is "picky" about the quality of certain items he consumes....Kashi cereal is pricey compared to the others, and so is Smart Balance milk and greek yogurt, just as examples. We eat a lot of fresh veggies (salads with practically every meal) and fruit, and meat. What we DON'T eat much of is starch: pasta, rice, breads.... the less expensive stuff that is easy to buy in bulk. :(
In the warmer months we have frequent get-to-gethers around the pool where we supply most or all of the food and beverages (including beer/wine).
I have recently started really clamping down on the grocery budget, however, and the last month or two we managed to stay below $900..... but of course, I was fully stocked on laundry soap, dishwasher soap, toilet tissue and paper towels, dog food, and medications already... so I didn't have to buy any of that stuff.
I do find that the fewer trips I make, the less I spend overall. But I also watch the sales flyers and stock up on "stock-up-able" items when they are discounted and I have coupons. (Especially toilet tissue, paper towels, ziploc bags, feminine products, laundry soap, etc).
We are a family of 4 (two tweens's, a girl and a boy- who stays hungry all the time, lol) and a large breed dog.