after they taken the rodent the whole way down and you can see a noticeable lump. then that's a good size meal. I also offer twice a week. when they had enough, most will stop feeding for a little while. usually known as the 900 gram wall they hit. but some will go right threw that wall. if you think you're feeding too much, you will be able to tell just by looking at the snake. don't go by general guidelines, go by the condition of the snake (length to weight).