When to size up (BG)?

dNoodle

(Typing on Droid) How do I know when it's time to move up a size? Or if the bigger diaper fits or not? Right now we are using BG AIOs in XS, and we have a few S and a whole bunch of OS. My baby weighs a little under 9lbs, and those OSs look like they're never going to fit! I want to size up as soon as we can because our XS stash is tiny (10). We are doing laundry 1-2 times a day and have to put them in the dryer, so they're getting beat. I want to move into the larger stash so that we can do a little less laundry and care for them properly.