Hadlock Estimated Measurements by Weeks Gestation

Expected ultrasound measurements (mm) based on weeks gestation.

Hadlock Formulas: Haddlock Radiology 1984; 152: 497-501

Weeks	BPD (mm)	HC (mm)	AC (mm)	FL (mm)
16	32.3	124.4	99.1	20.5
16.5	34.2	131.2	105.5	22.1
17	36.0	137.9	111.9	23.7
17.5	37.7	144.5	118.2	25.2
18	39.5	151.1	124.5	26.7
18.5	41.3	157.7	130.7	28.3
19	43.0	164.1	136.9	29.8
19.5	44.7	170.5	143.0	31.2
20	46.4	176.8	149.1	32.7
20.5	48.1	183.0	155.1	34.1
21	49.7	189.2	161.1	35.6
21.5	51.4	195.3	167.0	37.0
22	53.0	201.3	172.9	38.4
22.5	54.6	207.2	178.7	39.8
23	56.2	213.0	184.5	41.1
23.5	57.8	218.7	190.2	42.5
24	59.3	224.4	195.9	43.8
24.5	60.8	229.9	201.5	45.1
25	62.3	235.4	207.1	46.4
25.5	63.8	240.8	212.7	47.7
26	65.3	246.0	218.1	48.9
26.5	66.7	251.2	223.6	50.2
27	68.1	256.2	228.9	51.4
27.5	69.5	261.2	234.3	52.6
28	70.8	266.1	239.6	53.8
28.5	72.2	270.8	244.8	55.0
29	73.5	275.5	250.0	56.1
29.5	74.7	280.0	255.1	57.3
30	76.0	284.4	260.2	58.4
30.5	77.2	288.7	265.2	59.5
31	78.4	292.9	270.2	60.6
31.5	79.6	297.0	275.1	61.7
32	80.7	300.9	280.0	62.7
32.5	81.9	304.7	284.8	63.8
33	82.9	308.4	289.6	64.8
33.5	84.0	312.0	294.3	65.8
34	85.0	315.5	299.0	66.8
34.5	86.0	318.8	303.7	67.7
35	87.0	322.0	308.2	68.7
35.5	87.9	325.0	312.8	69.6
36	88.8	327.9	317.3	70.6
36.5	89.7	330.7	321.7	71.5
37	90.5	333.3	326.1	72.3
37.5	91.3	335.8	330.4	73.2
38	92.1	338.2	334.7	74.1
38.5	92.8	340.4	338.9	74.9
39	93.5	342.5	343.1	75.7
39.5	94.2	344.4	347.2	76.5
40	94.8	346.1	351.3	77.3
40.5	95.4	347.7	355.4	78.1
41	95.9	349.2	359.3	78.8
41.5	96.5	350.5	363.3	79.5
42	96.9	351.6	367.2	80.3