head circumference percentiles P3–P97, United Kingdom

United Kingdom’s published head circumference figures, P3 to P97 month by month, up to 18 years. Boys and girls separately.

boy

Age in years runs along the bottom and head circumference（cm） up the side. The five lines are, from the bottom, the 3rd, 15th, 50th, 85th and 97th percentiles, ranging from 35.1 to 60.5. The full figures are in the table above.

United Kingdom percentile curves for head circumference, boy.

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yearsmonths

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United Kingdom · head circumference, boy（cm）
Age	P3	P15	P50	P85	P97
1 months	35.1	36.1	37.3	38.5	39.5
2 months	36.9	37.9	39.1	40.3	41.3
3 months	38.3	39.3	40.5	41.7	42.7
4 months	39.4	40.4	41.6	42.9	43.9
5 months	40.3	41.3	42.6	43.8	44.8
6 months	41.0	42.1	43.3	44.6	45.6
7 months	41.7	42.7	44.0	45.3	46.3
8 months	42.2	43.2	44.5	45.8	46.9
9 months	42.6	43.7	45.0	46.3	47.4
10 months	43.0	44.1	45.4	46.7	47.8
11 months	43.4	44.4	45.8	47.1	48.2
12 months	43.6	44.7	46.1	47.4	48.5
13 months	43.9	45.0	46.3	47.7	48.8
14 months	44.1	45.2	46.6	47.9	49.0
15 months	44.3	45.5	46.8	48.2	49.3
16 months	44.5	45.6	47.0	48.4	49.5
17 months	44.7	45.8	47.2	48.6	49.7
18 months	44.9	46.0	47.4	48.7	49.9
19 months	45.0	46.2	47.5	48.9	50.0
20 months	45.2	46.3	47.7	49.1	50.2
21 months	45.3	46.4	47.8	49.2	50.4
22 months	45.4	46.6	48.0	49.4	50.5
23 months	45.6	46.7	48.1	49.5	50.7
2 years	45.7	46.8	48.3	49.7	50.8
2y 3m	46.0	47.2	48.6	50.0	51.2
2y 6m	46.3	47.5	48.9	50.4	51.6
2y 9m	46.6	47.8	49.2	50.7	51.9
3 years	46.8	48.0	49.5	50.9	52.1
3y 3m	47.0	48.2	49.7	51.2	52.4
3y 6m	47.2	48.4	49.9	51.4	52.6
3y 9m	47.3	48.5	50.1	51.6	52.8
4 years	49.5	50.7	52.2	53.7	55.0
4y 3m	49.6	50.8	52.4	53.9	55.1
4y 6m	49.7	51.0	52.5	54.0	55.3
4y 9m	49.8	51.1	52.6	54.2	55.4
5 years	49.9	51.2	52.7	54.3	55.6
5y 6m	50.1	51.4	53.0	54.5	55.8
6 years	50.3	51.6	53.2	54.8	56.1
6y 6m	50.5	51.8	53.4	55.0	56.3
7 years	50.6	51.9	53.5	55.1	56.5
7y 6m	50.8	52.1	53.7	55.3	56.6
8 years	50.9	52.2	53.9	55.5	56.8
8y 6m	51.1	52.4	54.0	55.7	57.0
9 years	51.2	52.5	54.2	55.8	57.2
9y 6m	51.3	52.7	54.3	56.0	57.3
10 years	51.5	52.8	54.5	56.1	57.5
10y 6m	51.6	53.0	54.6	56.3	57.7
11 years	51.8	53.1	54.8	56.5	57.8
11y 6m	51.9	53.3	55.0	56.6	58.0
12 years	52.1	53.4	55.1	56.8	58.2
12y 6m	52.2	53.6	55.3	57.0	58.4
13 years	52.4	53.8	55.5	57.2	58.6
13y 6m	52.6	54.0	55.7	57.4	58.8
14 years	52.7	54.1	55.9	57.6	59.0
14y 6m	52.9	54.3	56.0	57.8	59.2
15 years	53.1	54.5	56.2	58.0	59.4
15y 6m	53.3	54.7	56.4	58.2	59.6
16 years	53.4	54.8	56.6	58.3	59.8
16y 6m	53.6	55.0	56.8	58.5	60.0
17 years	53.7	55.2	56.9	58.7	60.1
17y 6m	53.9	55.3	57.1	58.9	60.3
18 years	54.0	55.5	57.3	59.0	60.5

girl

Age in years runs along the bottom and head circumference（cm） up the side. The five lines are, from the bottom, the 3rd, 15th, 50th, 85th and 97th percentiles, ranging from 34.3 to 58.1. The full figures are in the table above.

United Kingdom percentile curves for head circumference, girl.

Jump to age

yearsmonths

Download head circumference for every region as CSV

United Kingdom · head circumference, girl（cm）
Age	P3	P15	P50	P85	P97
1 months	34.3	35.3	36.5	37.8	38.8
2 months	36.0	37.0	38.3	39.5	40.5
3 months	37.2	38.2	39.5	40.8	41.9
4 months	38.2	39.3	40.6	41.9	43.0
5 months	39.0	40.1	41.5	42.8	43.9
6 months	39.7	40.8	42.2	43.5	44.6
7 months	40.4	41.5	42.8	44.2	45.3
8 months	40.9	42.0	43.4	44.7	45.9
9 months	41.3	42.4	43.8	45.2	46.3
10 months	41.7	42.8	44.2	45.6	46.8
11 months	42.0	43.2	44.6	46.0	47.1
12 months	42.3	43.5	44.9	46.3	47.5
13 months	42.6	43.8	45.2	46.6	47.7
14 months	42.9	44.0	45.4	46.8	48.0
15 months	43.1	44.2	45.7	47.1	48.2
16 months	43.3	44.4	45.9	47.3	48.5
17 months	43.5	44.6	46.1	47.5	48.7
18 months	43.6	44.8	46.2	47.7	48.8
19 months	43.8	45.0	46.4	47.8	49.0
20 months	44.0	45.1	46.6	48.0	49.2
21 months	44.1	45.3	46.7	48.2	49.4
22 months	44.3	45.4	46.9	48.3	49.5
23 months	44.4	45.6	47.0	48.5	49.7
2 years	44.6	45.7	47.2	48.6	49.8
2y 3m	44.9	46.1	47.6	49.0	50.2
2y 6m	45.3	46.5	47.9	49.4	50.6
2y 9m	45.6	46.8	48.2	49.7	50.9
3 years	45.9	47.0	48.5	50.0	51.2
3y 3m	46.1	47.3	48.7	50.2	51.4
3y 6m	46.3	47.5	49.0	50.4	51.6
3y 9m	46.5	47.7	49.2	50.6	51.8
4 years	48.9	49.9	51.1	52.3	53.4
4y 3m	49.0	50.0	51.3	52.5	53.5
4y 6m	49.2	50.2	51.4	52.6	53.7
4y 9m	49.3	50.3	51.5	52.8	53.8
5 years	49.4	50.4	51.7	52.9	53.9
5y 6m	49.7	50.7	51.9	53.2	54.2
6 years	49.9	50.9	52.2	53.4	54.4
6y 6m	50.1	51.1	52.4	53.6	54.6
7 years	50.3	51.4	52.6	53.9	54.9
7y 6m	50.5	51.6	52.8	54.1	55.1
8 years	50.7	51.7	53.0	54.3	55.3
8y 6m	50.9	51.9	53.2	54.5	55.5
9 years	51.1	52.1	53.4	54.7	55.7
9y 6m	51.2	52.3	53.6	54.9	55.9
10 years	51.4	52.4	53.7	55.0	56.1
10y 6m	51.5	52.6	53.9	55.2	56.3
11 years	51.7	52.7	54.1	55.4	56.5
11y 6m	51.8	52.9	54.2	55.5	56.6
12 years	51.9	53.0	54.4	55.7	56.8
12y 6m	52.0	53.1	54.5	55.9	57.0
13 years	52.1	53.3	54.6	56.0	57.1
13y 6m	52.2	53.4	54.8	56.1	57.3
14 years	52.4	53.5	54.9	56.3	57.4
14y 6m	52.5	53.6	55.0	56.4	57.5
15 years	52.6	53.7	55.1	56.5	57.7
15y 6m	52.6	53.8	55.2	56.6	57.8
16 years	52.7	53.9	55.3	56.7	57.9
16y 6m	52.8	54.0	55.4	56.9	58.0
17 years	52.9	54.1	55.5	57.0	58.1

About this table

A measurement taken at birth is read against gestational age, not age since birth, because WHO 2006 does not cover gestation. A baby who is already two weeks old is past that entry point and is read by age like any other.
UK-WHO is a spliced system: WHO 2006 from 2 weeks to 4 years, UK90 from 4 years up, and UK90’s gestational-age reference for measurements taken at birth.