Plan a healthy and varied menu for one week (three meals a day plus snacks) and write it down. Figure out how much food it will take to prepare your week’s menu and make a shopping list. Go to the grocery store with your list and write down the cost of each item. When you return home, total the cost of the items necessary to prepare your food for the week. Then multiply it by 4.5 to get the cost of groceries for one month.