For our suggested sizing guidelines, please see our sizing chart available on our product page that will provide an approximate guideline to choose an appropriate size for your baby. The Magic Sleepsuit is available in Small 3-6 months (12-18 lbs.), and Large 6-9 months (18-21 lbs.).
Babies are all different sizes and shapes, so the weight ranges are just guidelines. It is not recommended to size up. Please understand that sizing up can compromise the safety of the Sleepsuit. When the Sleepsuit is too big, babies can have too much wiggle room and may have the ability to wiggle out all together. Additionally, the Magic Sleepsuit will not do what it is intended to do if it does not fit properly.
For hip health, the Magic Sleepsuit should fit such that your baby is able to externally rotate hips/legs (feet turned out). Proper fit is critical to the safety and effectiveness of the Magic Sleepsuit.
Please reach out to us with any sizing questions, and feel free to email us a picture of your baby in the Magic Sleepsuit for a visual sizing assessment.