Boys Head Circumference-for-age (3rd through 97th percentiles)
3rd Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
31.48762 |
| 0.5 |
33.25006 |
| 1.5 |
35.78126 |
| 2.5 |
37.5588 |
| 3.5 |
38.89944 |
| 4.5 |
39.95673 |
| 5.5 |
40.81642 |
| 6.5 |
41.53109 |
| 7.5 |
42.13521 |
| 8.5 |
42.65253 |
| 9.5 |
43.10009 |
| 10.5 |
43.49049 |
| 11.5 |
43.83332 |
| 12.5 |
44.136 |
| 13.5 |
44.40441 |
| 14.5 |
44.64328 |
| 15.5 |
44.85646 |
| 16.5 |
45.04712 |
| 17.5 |
45.2179 |
| 18.5 |
45.37104 |
| 19.5 |
45.50843 |
| 20.5 |
45.63169 |
| 21.5 |
45.74221 |
| 22.5 |
45.84121 |
| 23.5 |
45.92974 |
| 24.5 |
46.00872 |
| 25.5 |
46.07898 |
| 26.5 |
46.14124 |
| 27.5 |
46.19614 |
| 28.5 |
46.24425 |
| 29.5 |
46.2861 |
| 30.5 |
46.32214 |
| 31.5 |
46.3528 |
| 32.5 |
46.37844 |
| 33.5 |
46.39942 |
| 34.5 |
46.41605 |
| 35.5 |
46.4286 |
| 36 |
46.43344 |
5th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
32.14881 |
| 0.5 |
33.83392 |
| 1.5 |
36.26428 |
| 2.5 |
37.97959 |
| 3.5 |
39.27893 |
| 4.5 |
40.30766 |
| 5.5 |
41.14714 |
| 6.5 |
41.84742 |
| 7.5 |
42.44134 |
| 8.5 |
42.95162 |
| 9.5 |
43.39458 |
| 10.5 |
43.7823 |
| 11.5 |
44.12399 |
| 12.5 |
44.42679 |
| 13.5 |
44.69639 |
| 14.5 |
44.93733 |
| 15.5 |
45.15333 |
| 16.5 |
45.34746 |
| 17.5 |
45.52229 |
| 18.5 |
45.67997 |
| 19.5 |
45.82234 |
| 20.5 |
45.95096 |
| 21.5 |
46.06719 |
| 22.5 |
46.17221 |
| 23.5 |
46.26704 |
| 24.5 |
46.35259 |
| 25.5 |
46.42963 |
| 26.5 |
46.49889 |
| 27.5 |
46.56098 |
| 28.5 |
46.61646 |
| 29.5 |
46.66583 |
| 30.5 |
46.70954 |
| 31.5 |
46.74801 |
| 32.5 |
46.78159 |
| 33.5 |
46.81061 |
| 34.5 |
46.8354 |
| 35.5 |
46.85621 |
| 36 |
46.86521 |
10th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
33.08389 |
| 0.5 |
34.67253 |
| 1.5 |
36.97377 |
| 2.5 |
38.60724 |
| 3.5 |
39.85123 |
| 4.5 |
40.84114 |
| 5.5 |
41.65291 |
| 6.5 |
42.3333 |
| 7.5 |
42.91311 |
| 8.5 |
43.41365 |
| 9.5 |
43.85025 |
| 10.5 |
44.23432 |
| 11.5 |
44.57454 |
| 12.5 |
44.87767 |
| 13.5 |
45.14908 |
| 14.5 |
45.3931 |
| 15.5 |
45.61325 |
| 16.5 |
45.81245 |
| 17.5 |
45.99315 |
| 18.5 |
46.15739 |
| 19.5 |
46.30692 |
| 20.5 |
46.44325 |
| 21.5 |
46.56767 |
| 22.5 |
46.68129 |
| 23.5 |
46.78511 |
| 24.5 |
46.87997 |
| 25.5 |
46.96663 |
| 26.5 |
47.04578 |
| 27.5 |
47.11801 |
| 28.5 |
47.18385 |
| 29.5 |
47.24379 |
| 30.5 |
47.29824 |
| 31.5 |
47.34761 |
| 32.5 |
47.39225 |
| 33.5 |
47.43247 |
| 34.5 |
47.46857 |
| 35.5 |
47.50081 |
| 36 |
47.51556 |
25th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
34.46952 |
| 0.5 |
35.93987 |
| 1.5 |
38.07878 |
| 2.5 |
39.60637 |
| 3.5 |
40.77713 |
| 4.5 |
41.71483 |
| 5.5 |
42.48889 |
| 6.5 |
43.14204 |
| 7.5 |
43.70245 |
| 8.5 |
44.18964 |
| 9.5 |
44.61764 |
| 10.5 |
44.99694 |
| 11.5 |
45.33549 |
| 12.5 |
45.63952 |
| 13.5 |
45.91398 |
| 14.5 |
46.16284 |
| 15.5 |
46.38937 |
| 16.5 |
46.59626 |
| 17.5 |
46.78578 |
| 18.5 |
46.95981 |
| 19.5 |
47.11999 |
| 20.5 |
47.26769 |
| 21.5 |
47.40413 |
| 22.5 |
47.53035 |
| 23.5 |
47.64724 |
| 24.5 |
47.75563 |
| 25.5 |
47.85621 |
| 26.5 |
47.94962 |
| 27.5 |
48.0364 |
| 28.5 |
48.11707 |
| 29.5 |
48.19206 |
| 30.5 |
48.26178 |
| 31.5 |
48.3266 |
| 32.5 |
48.38684 |
| 33.5 |
48.44281 |
| 34.5 |
48.49479 |
| 35.5 |
48.54301 |
| 36 |
48.56578 |
50th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
35.81367 |
| 0.5 |
37.19361 |
| 1.5 |
39.20743 |
| 2.5 |
40.65233 |
| 3.5 |
41.76517 |
| 4.5 |
42.66116 |
| 5.5 |
43.40489 |
| 6.5 |
44.0361 |
| 7.5 |
44.58097 |
| 8.5 |
45.05761 |
| 9.5 |
45.47908 |
| 10.5 |
45.85506 |
| 11.5 |
46.19295 |
| 12.5 |
46.49853 |
| 13.5 |
46.77638 |
| 14.5 |
47.03018 |
| 15.5 |
47.26295 |
| 16.5 |
47.47721 |
| 17.5 |
47.67504 |
| 18.5 |
47.85821 |
| 19.5 |
48.02822 |
| 20.5 |
48.18637 |
| 21.5 |
48.33377 |
| 22.5 |
48.4714 |
| 23.5 |
48.60011 |
| 24.5 |
48.72065 |
| 25.5 |
48.83367 |
| 26.5 |
48.93976 |
| 27.5 |
49.03945 |
| 28.5 |
49.13321 |
| 29.5 |
49.22146 |
| 30.5 |
49.30458 |
| 31.5 |
49.38292 |
| 32.5 |
49.45678 |
| 33.5 |
49.52645 |
| 34.5 |
49.59218 |
| 35.5 |
49.65423 |
| 36 |
49.68394 |
75th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
37.00426 |
| 0.5 |
38.32125 |
| 1.5 |
40.24987 |
| 2.5 |
41.63968 |
| 3.5 |
42.71455 |
| 4.5 |
43.58358 |
| 5.5 |
44.30801 |
| 6.5 |
44.92555 |
| 7.5 |
45.46104 |
| 8.5 |
45.93166 |
| 9.5 |
46.34979 |
| 10.5 |
46.72463 |
| 11.5 |
47.06318 |
| 12.5 |
47.37091 |
| 13.5 |
47.65214 |
| 14.5 |
47.91038 |
| 15.5 |
48.14848 |
| 16.5 |
48.36881 |
| 17.5 |
48.57336 |
| 18.5 |
48.76379 |
| 19.5 |
48.94153 |
| 20.5 |
49.10781 |
| 21.5 |
49.2637 |
| 22.5 |
49.4101 |
| 23.5 |
49.54784 |
| 24.5 |
49.67762 |
| 25.5 |
49.80008 |
| 26.5 |
49.91578 |
| 27.5 |
50.02521 |
| 28.5 |
50.12883 |
| 29.5 |
50.22705 |
| 30.5 |
50.32023 |
| 31.5 |
50.40869 |
| 32.5 |
50.49275 |
| 33.5 |
50.57267 |
| 34.5 |
50.6487 |
| 35.5 |
50.72108 |
| 36 |
50.75597 |
90th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
37.97379 |
| 0.5 |
39.24989 |
| 1.5 |
41.12605 |
| 2.5 |
42.48436 |
| 3.5 |
43.53902 |
| 4.5 |
44.39472 |
| 5.5 |
45.11034 |
| 6.5 |
45.72225 |
| 7.5 |
46.25443 |
| 8.5 |
46.72349 |
| 9.5 |
47.14142 |
| 10.5 |
47.51714 |
| 11.5 |
47.85744 |
| 12.5 |
48.16763 |
| 13.5 |
48.45191 |
| 14.5 |
48.71371 |
| 15.5 |
48.95578 |
| 16.5 |
49.18045 |
| 17.5 |
49.38963 |
| 18.5 |
49.58497 |
| 19.5 |
49.76786 |
| 20.5 |
49.93948 |
| 21.5 |
50.10089 |
| 22.5 |
50.25298 |
| 23.5 |
50.39655 |
| 24.5 |
50.53229 |
| 25.5 |
50.66082 |
| 26.5 |
50.78269 |
| 27.5 |
50.89839 |
| 28.5 |
51.00836 |
| 29.5 |
51.113 |
| 30.5 |
51.21268 |
| 31.5 |
51.3077 |
| 32.5 |
51.39837 |
| 33.5 |
51.48496 |
| 34.5 |
51.56771 |
| 35.5 |
51.64686 |
| 36 |
51.68514 |
95th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
38.51574 |
| 0.5 |
39.77262 |
| 1.5 |
41.62581 |
| 2.5 |
42.97189 |
| 3.5 |
44.01984 |
| 4.5 |
44.87197 |
| 5.5 |
45.58593 |
| 6.5 |
46.19736 |
| 7.5 |
46.72983 |
| 8.5 |
47.1997 |
| 9.5 |
47.6188 |
| 10.5 |
47.99592 |
| 11.5 |
48.33781 |
| 12.5 |
48.64972 |
| 13.5 |
48.93584 |
| 14.5 |
49.19955 |
| 15.5 |
49.44362 |
| 16.5 |
49.67034 |
| 17.5 |
49.88166 |
| 18.5 |
50.07919 |
| 19.5 |
50.26432 |
| 20.5 |
50.43825 |
| 21.5 |
50.60203 |
| 22.5 |
50.75654 |
| 23.5 |
50.90258 |
| 24.5 |
51.04085 |
| 25.5 |
51.17196 |
| 26.5 |
51.29647 |
| 27.5 |
51.41485 |
| 28.5 |
51.52756 |
| 29.5 |
51.63499 |
| 30.5 |
51.73749 |
| 31.5 |
51.83539 |
| 32.5 |
51.92898 |
| 33.5 |
52.01853 |
| 34.5 |
52.10429 |
| 35.5 |
52.18646 |
| 36 |
52.22628 |
97th Percentile
| Age
(in months) |
Head Circumference (in centimeters) |
| 0 |
38.85417 |
| 0.5 |
40.10028 |
| 1.5 |
41.94138 |
| 2.5 |
43.28181 |
| 3.5 |
44.32733 |
| 4.5 |
45.17877 |
| 5.5 |
45.893 |
| 6.5 |
46.50524 |
| 7.5 |
47.0388 |
| 8.5 |
47.5099 |
| 9.5 |
47.93027 |
| 10.5 |
48.30867 |
| 11.5 |
48.65181 |
| 12.5 |
48.96494 |
| 13.5 |
49.25225 |
| 14.5 |
49.51712 |
| 15.5 |
49.76233 |
| 16.5 |
49.99018 |
| 17.5 |
50.20261 |
| 18.5 |
50.40125 |
| 19.5 |
50.58751 |
| 20.5 |
50.76259 |
| 21.5 |
50.92752 |
| 22.5 |
51.08322 |
| 23.5 |
51.23047 |
| 24.5 |
51.36998 |
| 25.5 |
51.50236 |
| 26.5 |
51.62817 |
| 27.5 |
51.7479 |
| 28.5 |
51.86198 |
| 29.5 |
51.97081 |
| 30.5 |
52.07475 |
| 31.5 |
52.17413 |
| 32.5 |
52.26923 |
| 33.5 |
52.36032 |
| 34.5 |
52.44764 |
| 35.5 |
52.53143 |
| 36 |
52.57205 |