I feed 1 prey item (preferably rats) about the width of my snake at its widest point every 5 days until around 700-800 grams. Then the same thing except every 7 days. Prey item size increases with the size of the snake.
My mouse eater is about 140g and takes a weaned mouse every 5 days. He could probably go up to an small-medium adult mouse. The only reason he isn't is cause I have some cornsnakes in that prey item size and it's easier when it comes to ordering food.