After preemie and newborn sizes, just about all baby clothes come with relatively age-specific size labels starting with 0 to 3 months and continuing up in 3-month increments throughout the first year. This approach to sizing seems very straightforward—until you actually have a baby of your own and start putting the labels to the test. You’ll quickly find that one manufacturer’s idea of newborn doesn’t always match another’s, and that many newborns don’t fit in newborn-sized clothing at all. Some may fit into size 0 to 3 months from day 1 and size 3 to 6 months within weeks of being born. While it’s theoretically possible to take a baby into a fitting room and try clothes on to see if they fit, we find the thought of actually doing so quite comical and have yet to meet anyone who has ever done it! If you want to come away with a few practical pieces of sizing advice, we suggest you consider the following:
If a label reads 3 to 6 months, an average-sized baby is more likely to fit in it around 3 months of age. We definitely don’t recommend holding your breath for it to fit at 6 months.
Look for tags that offer weight and height guidelines as well as age ranges, as they can give you a better sense of how the clothing will actually fit your baby.
Remember that sizing varies by brand. Just as with adult clothing, some brands run big and others run small. Once you become familiar with one or several brands, you’ll have an easier time gauging what size your baby needs relative to the specific brand.