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Crochet baby hat size chart

Pick a baby age to get the finished hat circumference, height and crown circle for your pattern.

Crochet hat size calculator

10%

Hats stretch, so make them smaller than the head.

Finished hat circumference
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Head circumference
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Enter your head measurement to see your size in every system.

Crochet baby hat sizes

Baby hats use about 10% negative ease so they stay on without squeezing. Measure the baby if you can, especially for preemies, whose sizes vary widely.

Crochet baby hat sizes
AgeHead (cm / in)Hat (cm / in)HeightCrown
Preemie 25–32 / 9.8–12.6 25.7 / 10.1 11.4 cm / 4.5 in 8.2 cm / 3.21 in
Newborn 32–36 / 12.6–14.2 30.6 / 12 14 cm / 5.5 in 9.7 cm / 3.83 in
0 to 3 months 35–40.5 / 13.8–15.9 34 / 13.4 15.2 cm / 6 in 10.8 cm / 4.26 in
3 to 6 months 39.5–43.5 / 15.6–17.1 37.4 / 14.7 16.5 cm / 6.5 in 11.9 cm / 4.68 in
6 to 12 months 42–47 / 16.5–18.5 40.1 / 15.8 17.8 cm / 7 in 12.7 cm / 5.02 in
Toddler (1 to 2 years) 45–49 / 17.7–19.3 42.3 / 16.7 19.1 cm / 7.5 in 13.5 cm / 5.3 in
2 to 4 years 47.5–51 / 18.7–20.1 44.3 / 17.5 20.3 cm / 8 in 14.1 cm / 5.55 in

Crown circle and height

Work the flat circle until it reaches the crown diameter in the chart, then work even until the hat reaches the height. For a folded brim, add the brim depth twice. For an earflap hat, measure the height to the top of the ear and add the flaps separately.

Fit tips

  • Use soft, washable yarn such as cotton or superwash merino for babies.
  • Avoid long ties and loose pompoms on hats for young babies.

How to measure your head

  1. 1 Use a soft tape measure, or a string and a ruler.
  2. 2 Wrap it around your head where the hat will sit: about 1 cm (⅜ in) above your ears and across the middle of your forehead.
  3. 3 Keep the tape level and snug, not tight. Do not pull it in.
  4. 4 Read the number where the tape overlaps. Measure two or three times and use the largest value.
  5. 5 Type the number into the calculator, or find it in the chart.
How to measure

Frequently asked questions

What size is a newborn crochet hat?

About 30.5 cm (12 in) around and 14 cm (5 ½ in) tall, for a head of 32 to 36 cm.

How big should a 3 to 6 month crochet hat be?

About 37.5 cm (14 ¾ in) around and 16.5 cm (6 ½ in) tall.

How do I size a crochet hat for a preemie?

Ask the hospital for its preferred sizes. Most preemie hats are 25 to 30 cm (10 to 12 in) around.

Related charts

All charts