This last document is a monster of my own making. The first sheet is a spreadsheet where you can input the weight in grams of various ingredients that you are adding to your own homemade diet. The second sheet compares the nutritional breakdown of your homemade recipe (that you inputed onto the first sheet) with commercially available diets. The last is a nutritional breakdown of various ingredients that ive looked into as food sources over the years.
So its generally accepted that between 2:1 is ideal, lower calcium levels than that and the phosphorus inhibits the absorption of calcium. I find that with the girls laying eggs all the time, 3:1 is closer to what I am giving them after supplementation.