Baby length chart by month

This chart shows the WHO length-for-age percentiles for baby girls and boys from birth to 24 months, in cm with in for the median. Use the calculator below to find your baby’s length percentile for their exact age. Separate charts in cm and inches: baby boy length chart · baby girl length chart.

Sex

Units

Date of birth Date measured Weight (kg) Length (cm) Head circumference (cm)

Chart

Enter a date of birth and at least one measurement to see the percentile.

Key numbers

At birth, the WHO median length is 49.1 cm (19.3 in) for girls and 49.9 cm (19.6 in) for boys.
At 6 months, the median is 65.7 cm (25.9 in) for girls and 67.6 cm (26.6 in) for boys.
At 12 months, the median is 74.0 cm (29.1 in) for girls and 75.7 cm (29.8 in) for boys.
At 24 months, the median is 86.4 cm (34.0 in) for girls and 87.8 cm (34.6 in) for boys.
In the first year, median length grows by about 24.9 cm for girls and 25.9 cm for boys, and 67% of that first-year growth happens in the first 6 months.

Girls: average length and percentiles by month (WHO)

Values in cm at each percentile. The median is the average length for that age; it is also shown in in.

Age	3th	15th	Median	85th	97th	Median (in)
Birth	45.6	47.2	49.1	51.1	52.7	19.3
1 month	50.0	51.7	53.7	55.7	57.4	21.1
2 months	53.2	55.0	57.1	59.2	60.9	22.5
3 months	55.8	57.6	59.8	62.0	63.8	23.5
4 months	58.0	59.8	62.1	64.3	66.2	24.4
5 months	59.9	61.7	64.0	66.3	68.2	25.2
6 months	61.5	63.4	65.7	68.1	70.0	25.9
7 months	62.9	64.9	67.3	69.7	71.6	26.5
8 months	64.3	66.3	68.7	71.2	73.2	27.1
9 months	65.6	67.6	70.1	72.7	74.7	27.6
10 months	66.8	68.9	71.5	74.0	76.1	28.1
11 months	68.0	70.1	72.8	75.4	77.5	28.6
12 months	69.1	71.3	74.0	76.7	78.9	29.1
13 months	70.2	72.5	75.2	78.0	80.2	29.6
14 months	71.3	73.6	76.4	79.2	81.5	30.1
15 months	72.3	74.7	77.5	80.4	82.7	30.5
16 months	73.3	75.7	78.6	81.5	83.9	30.9
17 months	74.3	76.7	79.7	82.6	85.1	31.4
18 months	75.2	77.7	80.7	83.7	86.2	31.8
19 months	76.1	78.6	81.7	84.8	87.3	32.2
20 months	77.0	79.6	82.7	85.8	88.4	32.6
21 months	77.9	80.5	83.7	86.9	89.5	32.9
22 months	78.7	81.3	84.6	87.9	90.5	33.3
23 months	79.5	82.2	85.5	88.8	91.5	33.7
24 months	80.3	83.1	86.4	89.8	92.5	34.0

Boys: average length and percentiles by month (WHO)

Values in cm at each percentile. The median is the average length for that age; it is also shown in in.

Age	3th	15th	Median	85th	97th	Median (in)
Birth	46.3	47.9	49.9	51.8	53.4	19.6
1 month	51.1	52.7	54.7	56.7	58.4	21.5
2 months	54.7	56.4	58.4	60.5	62.2	23.0
3 months	57.6	59.3	61.4	63.5	65.3	24.2
4 months	60.0	61.7	63.9	66.0	67.8	25.2
5 months	61.9	63.7	65.9	68.1	69.9	25.9
6 months	63.6	65.4	67.6	69.8	71.6	26.6
7 months	65.1	66.9	69.2	71.4	73.2	27.2
8 months	66.5	68.3	70.6	72.9	74.7	27.8
9 months	67.7	69.6	72.0	74.3	76.2	28.3
10 months	69.0	70.9	73.3	75.6	77.6	28.9
11 months	70.2	72.1	74.5	77.0	78.9	29.3
12 months	71.3	73.3	75.7	78.2	80.2	29.8
13 months	72.3	74.4	76.9	79.4	81.5	30.3
14 months	73.4	75.5	78.0	80.6	82.7	30.7
15 months	74.4	76.5	79.1	81.8	83.9	31.2
16 months	75.3	77.5	80.2	82.9	85.1	31.6
17 months	76.2	78.5	81.2	84.0	86.3	32.0
18 months	77.1	79.4	82.3	85.1	87.4	32.4
19 months	78.0	80.4	83.2	86.1	88.5	32.8
20 months	78.8	81.2	84.2	87.2	89.6	33.1
21 months	79.7	82.1	85.1	88.2	90.6	33.5
22 months	80.5	83.0	86.0	89.1	91.6	33.9
23 months	81.2	83.8	86.9	90.1	92.7	34.2
24 months	82.0	84.6	87.8	91.0	93.6	34.6

How to read this chart

A percentile tells you how a measurement compares with other children of the same age and sex. At the 50th percentile (the median), half of children measure more and half measure less. At the 15th percentile, 15 out of 100 children measure less.

Anything between the 3rd and the 97th percentile is within the usual range on the WHO chart. Pediatricians pay more attention to the direction of the curve over several visits than to any single number: a baby who stays near the 15th percentile is usually growing just as steadily as one who stays near the 85th.

Percentiles here come from the official WHO LMS tables, calculated at each whole month. Between months, the calculator interpolates for your baby’s exact age.

Common questions

What is a normal length for a baby by age?

On the WHO standard, the 3rd to 97th percentile runs from 45.6–52.7 cm (18.0–20.7 in) for newborn girls and 46.3–53.4 cm (18.2–21.0 in) for newborn boys; at 3 months 55.8–63.8 cm (22.0–25.1 in) (girls) and 57.6–65.3 cm (22.7–25.7 in) (boys); at 6 months 61.5–70.0 cm (24.2–27.6 in) and 63.6–71.6 cm (25.0–28.2 in); at 12 months 69.1–78.9 cm (27.2–31.1 in) and 71.3–80.2 cm (28.1–31.6 in).

What is the average length (height) of a baby by month?

The WHO median, the middle of the range, is the usual "average". For boys it is 67.6 cm (26.6 in) at 6 months, 70.6 cm (27.8 in) at 8 months, 72.0 cm (28.3 in) at 9 months, 75.7 cm (29.8 in) at 12 months, 82.3 cm (32.4 in) at 18 months. For girls it is 65.7 cm (25.9 in) at 6 months, 68.7 cm (27.1 in) at 8 months, 70.1 cm (27.6 in) at 9 months, 74.0 cm (29.1 in) at 12 months, 80.7 cm (31.8 in) at 18 months. The tables below list every month.

How much do babies grow in the first year?

Going by the WHO medians, about 25 cm for girls and 26 cm for boys, which is roughly half of their birth length.

How do you measure a baby’s length?

Lay your baby flat on their back with legs straight and measure from the top of the head to the bottom of the heels. Length is measured lying down until age 2; after that, standing height is used.

Should I use the WHO or the CDC growth chart?

The CDC recommends the WHO growth charts for children under 2 years in the United States, and the CDC charts from age 2. The WHO charts describe how healthy breastfed babies grow in good conditions; the CDC charts describe a reference group of US children.

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