I know my original events that i use are 8 inches. I went with 9 because A:it was already an example set on my dope card that came with my scope and because i figured the events are on the smaller side so 9inches is probably a good average. Now with my dope card it was set up like a multiplication table. On top was target height and down the left side was number of mils occupied. The only problem was that the chart was set for maximum magnification which on my scope is 9x and it was reading im meters. So i copied just the 9 inch portion for 3x and in yards. I plan to do the 4' chart as well for pallets. That should be enough to always estimate range on the fly. Granted this doesnt take into account your elevation vs your targets elevation. Ill have to either do the work for that separately or just get a feel for it over time. Ill look into it but i have a feeling that neither you nor your target will ever be at enough of an incline or decline that it should matter more than a few mills over or under.