At what weight and height can my child transition from rear-facing to forward-facing?

Your child must exceed the rear-facing requirements of 1.8-18 kg (4-40 lbs) and 43-102 cm (17-40 in.) with the top of their head at least 2.5 cm (1 in.) below the headrest to transition to forward-facing. However, the American Academy of Pediatrics recommends keeping children rear-facing for as long as possible, and some states require rear-facing use until age 2. Once your child exceeds any rear-facing size requirement and is less than 2 years old, you must discontinue use of this restraint entirely. (Page 4)