Baby Garment Calculator — Yarn and Sizing for Baby Knits

These are Craft Yarn Council body chest measurements (the baby’s actual chest, not the finished garment): 3 months 40.5cm, 6 months 43cm, 12 months 45.5cm, 18 months 48cm, 24 months 50.5cm. Newborn is roughly 35.5cm. Finished garments add 3-5cm of positive ease on top of these for comfort and room to grow, so a 6-month jumper finishes around 48cm. Babies grow quickly, so sizing up is often wise.

A newborn cardigan in DK uses approximately 200-300m. A baby jumper uses 250-400m. A baby blanket uses 400-600m. Baby items are quick projects that use small amounts of yarn, making them ideal for luxury fibres you might not use for full-size garments.

Choose soft, machine-washable yarn. Superwash merino, cotton, bamboo blends, and quality acrylic are all suitable. Avoid mohair, angora, and very fuzzy yarns that babies could inhale. The yarn should be machine washable at 30-40C for practical care.

Baby garments need 3-5cm of positive ease at the chest. Babies need room to move and grow. Too-tight garments are uncomfortable and outgrown faster. Nappy bulk also requires extra room in the lower body. Some knitters add an extra size for room to grow.

Envelope necks or button shoulders allow easy dressing without pulling over the head. Snap buttons are faster than traditional buttons. Avoid ties and ribbons (choking hazard). Place buttons or snaps where they cannot press into the baby when lying down.