Little One Percentile

Where does your baby sit on the growth chart?

Point anywhere on the chart, or pick an age and percentile. No measurements needed. Add your baby’s numbers when you have them.

Exploring

At 13 weeks, a girl on the 50th percentile weighs 12 lb 14 oz.

57.51012.51517.520Birth1m2m3m4m5m6mlb97th90th75th50th25th10th3rd
Median (50th) 25th–75th 10th–90th 3rd–97thTap the chart to pin a point, then drag it.
13 weeks
Percentile

About 50 in 100 girls this age weigh less.

Compared with the median
Right on the median.
Nearest lines
75th is 1 lb 2 oz more25th is 1 lb 1 oz less
If staying on the 50th
4 months: ~14 lb 3 oz6 months: ~16 lb 1 oz9 months: ~18 lb 2 oz
Full table: girls' weight by age
Age3rd10th25th50th75th90th97th
Birth
7 days
2 weeks
3 weeks
4 weeks
5 weeks
6 weeks
7 weeks
8 weeks
9 weeks
10 weeks
11 weeks
12 weeks
13 weeks
4 months
5 months
6 months
7 months
8 months
9 months
10 months
11 months
1 year
1 year 3 months
1 year 6 months
1 year 9 months
2 years

What a percentile means

A baby on the 25th percentile for weight weighs more than 25 out of 100 healthy babies of the same age and sex, and less than the other 75. The 50th percentile is the median: half of babies are above it and half below. A low or high percentile is not good or bad by itself.

What the dashed line means

The dashed line shows where your baby would be if they stayed on the same percentile. It is not a prediction. Many babies move across percentile lines in the first months, especially between birth and 6 months. Doctors look at the pattern over several visits rather than one number.

Where the numbers come from

The WHO Child Growth Standards, calculated day by day from birth to 24 months. The CDC and the American Academy of Pediatrics recommend these charts for children under 2 in the US. Percentiles are computed exactly from the WHO’s published formulas, not read off a picture of a chart.