You bought the outfit in newborn size. The baby wore it twice. Then it did not fit.
Every mom has done this. The problem is not the brand. The problem is the label on the tag.
Age labels are the least reliable way to size a baby. Two babies born the same week often wear two different sizes by month three. One is long and lean. One is round and short. The tag says the same thing for both.
Weight is the number worth trusting. Here is how to use it.
Start with weight, then check height
Find your baby's current weight first. Match it to the size range. Use height as a second check if your baby is long for their weight.
| Size | Age range | Weight (lbs) | Height (in) |
|---|---|---|---|
| NB | Newborn | Up to 8 | Up to 21 |
| 0-3M | 0 to 3 months | 8 to 12 | 21 to 24 |
| 3-6M | 3 to 6 months | 12 to 17 | 24 to 27 |
| 6-12M | 6 to 12 months | 17 to 22 | 27 to 30 |
| 12-18M | 12 to 18 months | 22 to 27 | 30 to 32 |
| 18-24M | 18 to 24 months | 27 to 30 | 32 to 34 |
Our sizing runs the same across every piece in the line. Learn it once and you know it for everything you order from us.
Buying before the baby arrives
You do not have a weight yet. You have a due date and a guess.
The average newborn in the U.S. weighs around seven and a half pounds. Most babies outgrow newborn size within two to four weeks. Some skip it entirely.
So think about what you want the piece to do:
- Coming home outfit or newborn photos. Choose NB. You want the fit close for those first images.
- Something worn more than a handful of times. Choose 0 to 3M. It will be roomy for a week or two, then fit for months.
- Baby expected over eight pounds. Skip NB. Start at 0 to 3M.
If you are torn, 0 to 3M is the safer choice. A slightly big romper still photographs beautifully. A too-small one goes back in the drawer.
Buying as a gift
This is where sizing goes wrong most often.
Gift buyers reach for newborn because it looks small and sweet on the hanger. The baby wears it twice, then it goes in a box.
Size up instead.
- Baby shower gift, before the birth. Choose 3 to 6M. The baby grows into it, and the piece gets a full season of wear.
- Gift after the baby arrives. Look at current weight, then choose the next size up.
New moms have plenty of newborn clothes. What they run short on is the next size, right when the baby hits it. Give her the size nobody else thought to buy.
When your baby is between sizes
Size up.
Knitwear is cut with natural stretch and a little extra room. A snug fit today becomes an unwearable fit in three weeks. Babies grow faster than any of us plan for.
How to keep the fit you paid for
Machine drying on regular heat shrinks knitwear and pulls it out of shape. This is the most common reason a well fitting piece stops fitting, and it has nothing to do with sizing.
Here is what protects the fit:
- Wash cold.
- Lay flat to dry where you are able.
- If you use the dryer, tumble dry low.
- Follow the care label on each piece.
We would rather tell you this plainly than have a favorite romper come out of the dryer two sizes smaller. Knit needs a little more care than a cotton onesie. In return it holds its shape and softens with every wash.
Take the guide with you
We put all of this into a printable size and fit guide. The full chart, the gift sizing rules, and the care steps on two pages.
Keep it on your phone while you shop. Print it for the nursery. Send it to the grandparent who keeps asking what size to buy.
We are Gathered Lamb, a small family run brand making organic cotton knitwear for babies. Every piece is designed to be worn, washed, passed down, and loved. Ten percent of every sale goes to the Tim Tebow Foundation.
"He tends his flock like a shepherd. He gathers the lambs in his arms." Isaiah 40:11
