Here’s a link to the BP Husbandry section with a chart on feeding that gives some good rule of thumb guidelines on prey size and frequency.
https://ball-pythons.net/forums/show...ing-Guidelines
I personally don’t feed more than every 7 days with a prey item roughly 10-15% of the snake’s weight. I will also feed 2 smaller prey items when my snakes are transitioning to the next size up.