How to Choose a Baby Sweater Size When You're Buying Ahead
Sizing a hand-knit sweater is harder than sizing a T-shirt, for two reasons. You are usually buying for a child who isn't in front of you — sometimes for one who hasn't been born. And because every piece is knitted to order with a name in it, it isn't a garment you can swap for a different size later.
So it is worth getting right first time. This page tells you how.
Start here: add four inches
Our sweaters are a drop shoulder style, and every measurement below is the finished garment, not the child.
The one rule that matters
Measure the child's chest, add 4 inches, and pick the size whose chest measurement is closest.
That four inches is the ease — the room that makes a sweater a sweater rather than a compression layer. Skip it and you will order one size too small, which is the most common mistake we see.
To measure a chest: around the body, just under the arms, across the shoulder blades, with the child's arms held out to the sides.
Every size, with the numbers
If you don't have a child to measure — which is most people buying a gift — use the height and weight columns instead. They are the more reliable guide for babies.
Babies
| Size | Chest (in) | Height (in) | Weight (lb) | Total length (in) |
|---|---|---|---|---|
| Preemie | 16.5 | 0–16 | 0–5 | 9.5 |
| Newborn | 18.75 | 17–23 | 6–12 | 10.5 |
| 6 Months | 20.5 | 24–27 | 13–18 | 11.5 |
| 12 Months | 23 | 28–32 | 19–22 | 12 |
| 18 Months | 25 | 33–36 | 23–26 | 13 |
Toddlers
| Size | Chest (in) | Height (in) | Weight (lb) | Total length (in) |
|---|---|---|---|---|
| 2T | 26.5 | 37–41 | 27–29 | 14 |
| 3T | 28 | 42–44 | 30–34 | 15 |
| 4T | 29 | 45–48 | 35–40 | 15.5 |
| 5T | 30 | 49–52 | 41–46 | 16.5 |
Older children
| Size | Chest (in) | Height (in) | Weight (lb) | Total length (in) |
|---|---|---|---|---|
| 6T (6 years) | 31 | 53–56 | 47–50 | 17 |
| 8T (8 years) | 32.5 | 57–60 | 51–60 | 18.5 |
| 10T (10 years) | 34 | 60–64 | 61–70 | 20.5 |
| 12T (12 years) | 36.5 | 65–70 | 71–80 | 21 |
Thirteen sizes, Preemie through to a twelve-year-old. It is genuinely possible to buy the same design for a child every few years and watch it grow with them.
Hats
Hats go by head circumference — a tape measure around the widest part, just above the ears.
| Size | Head circumference (in) | Hat length (in) |
|---|---|---|
| Preemie | 12 | 5 |
| Newborn | 13 | 5.75 |
| 3–6 Months | 14 | 6.25 |
| 6–12 Months | 15 | 7 |
| 12–18 Months | 16 | 7.5 |
| 2–4 Years | 17 | 7.75 |
| 5–8 Years | 18 | 8 |
| 9–12 Years | 19 | 8.5 |
| Adult | 20 | 8.75 |
Knitted hats stretch, so they are far more forgiving than sweaters. If you are between sizes on a hat, size up — it will still fit, and for longer.
Buying for a baby who hasn't been born
You have no measurements, so stop trying to find them. Work from the calendar instead.
A Newborn size fits for around the first six months. These are hand-knitted with room to grow, so the size lasts a good deal longer than the label suggests — and it covers the whole stretch when the baby is photographed most.
If you want the sweater worn rather than photographed once, go bigger:
- Baby due in spring or summer — order 6 Months or 12 Months. A newborn size arrives in warm weather and never gets used.
- Baby due in autumn or winter — Newborn works, but 6 Months will carry them through the cold end of the season.
- Buying at a shower, months ahead — 6 Months is the safe default. It is the size that is hardest to get wrong.
Buying ahead a season for a child you know
The trap here is ordering the size the child is wearing today for a sweater that arrives in three weeks and gets worn for the next six months.
Between about one and four, children gain roughly a size a year, and most of it lands in height rather than chest. Because these are drop-shoulder sweaters, a size up reads as slightly roomy rather than wrong — the shoulder seam is meant to sit off the shoulder. If you are choosing between two sizes for a gift that has to last, take the larger one.
The exception is the going-home photo and the first birthday portrait. If the gift exists for one specific photograph, size for that day.
What if you get it wrong
Here is the honest answer, and the reason this page exists.
Before you order
Because every piece is knitted to order with a specific name on it, we can only accept returns on items that arrive defective. A sweater in the wrong size isn't defective, so it can't be exchanged — there is no shelf of other sizes to swap it for. If something does arrive faulty, email colleen@customknitsforbaby.com within 15 days and it will be put right.
Which means the five minutes you spend on sizing now is the whole ball game. And it is why we would much rather you asked first.
Just ask us
Genuinely — this is the fastest route to the right answer, and it costs you nothing.
Send the child's age, or their due date, or a chest measurement if you have one, and we will tell you which size to order before anything is cast on. Message us through the contact page or email colleen@customknitsforbaby.com.
Nobody has ever regretted asking. Plenty of people have regretted guessing.
Now pick your piece
Every size above is available on every name sweater, hand-knit to order in the USA.
- Personalized Baby Sweaters — sizes Preemie to 12T
- Custom Knit Hats — Preemie to Adult
- When to order so it arrives in time — if you're working to a date
Still unsure? Send us the due date or the child's age and we'll size it for you before we cast on.