Standard baby garment measurements by age, for sweaters, rompers and dresses.
| Size | Age | Chest (cm) | Garment length (cm) |
|---|---|---|---|
| Preemie | Premature | 28 – 31 | 25 – 28 |
| Newborn | 0 – 1 month | 32 – 34 | 28 – 31 |
| 0–3M | 0 – 3 months | 35 – 37 | 31 – 34 |
| 3–6M | 3 – 6 months | 38 – 40 | 34 – 38 |
| 6–9M | 6 – 9 months | 41 – 43 | 38 – 41 |
| 9–12M | 9 – 12 months | 44 – 46 | 41 – 44 |
| 12–18M | 12 – 18 months | 47 – 49 | 44 – 48 |
| 18–24M | 18 – 24 months | 50 – 52 | 48 – 52 |
Baby clothing sizes move fast in the first two years, and unlike adult sizing, small differences of a centimeter or two really matter for fit. Chest circumference is the key measurement for most crochet garments — sweaters, cardigans, rompers — while garment length determines where a piece hits on a growing baby. Use this chart as a baseline, and consider sizing up slightly for a longer wear window.
How much ease should I add to baby garment measurements?
For most crochet baby garments, add about 2.5-5cm of positive ease to the chest measurement for comfortable movement, unless the pattern already accounts for this.
Do babies grow out of sizes quickly?
Yes — babies often move up a size every 2-3 months in the first year. Many makers size up slightly or choose adjustable styles (like raglan sweaters) to extend wearability.
Where do I measure garment length from?
Garment length is usually measured from the highest point of the shoulder straight down to the hem, with the garment laid flat.