When will my preemie reach a normal weight and height?

24 months. Most babies will reach their expected growth curve by 2 years old, although those who were less premature will generally "catch up" sooner. If your child does not appear to be growing properly, your pediatrician will want to order some tests to determine if there is a treatable cause for the delay.
18-24 months. Very low birth weight babies (under 3 pounds 5 ounces), may take 24 months to reach normal length, but usually remain relatively thin. Low birth weight babies (3 pounds 6 ounces to 5 pounds 8 ounces) will usually catch up by 18 months.