Size

Head Circumference

Hat Circumference

Crown Circle Diameter

Hat Height -Top of Crown to Bottom of Ear

Preemie 1 – 2 pounds

9 – 10 inches/23 – 25 cm

7.5 – 8 inches/18 – 20 cm

1.75 – 2 inches/4 ½ – 5 cm

3 – 3.5 inches/ 8 – 9 1/2 cm

Preemie 2 – 3 pounds

10 – 11 ¼ inches/25 – 28 cm

8 1/2 – 10 inches/22 – 25 cm

2.0 – 2.25 inches/5 cm

3.5 inches/9 – 9 ½ cm

Preemie 4 – 5 pounds

11 ½ – 12 inches/28 – 30 cm

9 – 10 inches/23 – 25 cm

2.5 – 3 inches/ 6 ½ – 8 cm

3.5 – 4 inches/9 – 10 ½ cm

Preemie 5 ½ – 6 pounds

12 – 13 inches/30 – 33 cm

10 - 11 inches/25 – 28 cm

3.0 – 3.5 inches/7 ½ – 9 cm

4 – 4.5 inches/10 ½ – 11 ½ cm

Newborn

13 inches/33 cm

12 – 12.5 inches/30.5 – 32 cm

3.5 – 4.0 inches/9 – 10 ½ cm

4.5 – 5.5 inches/11 ½ – 14 cm

2 weeks – 3 months

14 inches/35.5 cm

13 – 13.5 inches/33 – 34.5 cm

4.45 – 4.75 inches/11-12.5 cm

5.5 – 6 inches/14 – 15 ½ cm

3 – 6 months

15 inches/36 cm

14 – 14.5 inches/35.5 – 37 cm

5 inches/ 13 cm

6 – 6.25 inches/15 ½ – 16 cm

6 – 9 months

16 inches/40.5 cm

15 inches/36 cm

5.25 inches/14 cm

6.25 – 6.5 inches/16 – 16 ½ cm

9 -12 months

16.5 inches/42 cm

15.5 inches/ 39.5 cm

5.25 – 5.5 inches/14 – 15 cm

6.5 inches/16 ½ cm

12-18 months

17 inches/43.5 cm

16 inches/ 40.5 cm

5.5 - 5.75 inches/15 cm

6.75 inches/ 17 ½ cm

18-24 months

18 inches/46 cm

17 inches/ 43.5 cm

5.75 – 6 inches/15 – 16 cm

7.25 inches/19 cm

2-5 years

18 – 19 inches/46 – 48.5 cm

17 – 18 inches/43.5 – 46 cm

6 – 6.25/16 cm

7.25 – 7.5 inches/ 19 cm

Child

19 – 20 inches/48.5 – 51 cm

18 – 19 inches/46 – 48.5 cm

6.25 – 6.5 inches/16 cm – 17 cm

7.75 – 8.0 inches/20 cm