I know most people feed their BPs rats based on the girth of the snake, but I still feel more comfortable doing it based on the weight of the snake and rat. I'm also visual, so I've tried to come up with a graph that makes it easy to correlate the snake's weight with the rat's weight. I've used a couple sources to create the graph:

http://ball-pythons.net/forums/showt...mparison-Chart

http://www.ballpythonz.net/feeding-ball-pythons/

I also assume the 10% rule for BPs weighing ≤ 650g

Please provide feedback and let me know if you think anything needs to be adjusted. And there's obviously some error band that would go around this curve, but I don't have a good feel for how to estimate that. Maybe a ±5% is reasonable?