A 5 week old boy, size 65 cm.
A 6 week old girl, size 65 cm.
One size, called Size 1 (birth to 12 months so they say, but we think more like birth to 6 months depending on the baby)
Size note from Karen: I think the size jump happens much sooner than at age 1 that the tag says. I would change up to size 75 cm at 4 months old. But I like to felt (shrink) my wool sleepsack to get more moisture-resistance. Felting shrinks it and makes it thicker and more dense, which I prefer in my family bed. I felt the wool this by rubbing the wool fibers with my hands while the wool is wet with some woolwash. You don't have to do this. You can leave the wool soft and stretchy. I think the size jump is sooner and it can even be possible to start a newborn in size 75 especially if you want to felt it, or if you don't mind it big at first. A size 75 cm will be very long on a newborn but it can make sense so that you buy only one of them. But, on the other hand the right size at the right age is the best fit. Also consider that once babies begin to roll over and crawl, sleepsacks are inconvenient on a moving baby. Some babies still love them as toddlers, but others will not want a sleepsack once they become mobile. So, the baby's personality plays a factor here. But then again, you can felt and shrink it, so, the size is a decision to make.
See wool washing info page. When you order from us, you will get a 2 page sheet with detailed instructions and information about wool included with your order automatically.