Do you guys follow a general rule of thumb when it comes to what sized rat you feed your BP when it comes to weight (grams)? Do you feed a certain sized rat until lets say 500 grams, then go up a size after 1000g?

I need to buy rats at the end of the month and need to know what size to buy in bulk. My male is 270 grams and my female is 650. He is getting too big for rat pups, so I am going to switch him to weened rats, and she looks like she can doesn't have a problem with the larger weened rats.

I know not to feed larger than the snake is wide.But is there any guide by grams?

Thanks,