Weight percentiles for a 11-month-old boy

For a 11-month-old boy, the WHO median weight (50th percentile) is 9.4 kg. Most healthy boys this age weigh between 7.7 kg and 11.5 kg, the 3rd and 97th percentiles.

Percentile table

Percentile	Value	Imperial
3rd	7.7 kg	16.9 lb
5th	7.9 kg	17.3 lb
15th	8.4 kg	18.5 lb
25th	8.7 kg	19.3 lb
50th (median)	9.4 kg	20.8 lb
75th	10.1 kg	22.3 lb
85th	10.5 kg	23.2 lb
95th	11.2 kg	24.8 lb
97th	11.5 kg	25.4 lb

Values from the WHO table, rounded to one decimal.

Source: WHO Child Growth Standards, weight-for-age table. Every value on this page is checked automatically against the published WHO table before publishing, and the calculator uses WHO's LMS method. Updated October 2, 2026. Corrections and questions: ahozon@benbasha.com

Percentile calculator

Enter your child's measurement to see the WHO percentile. It uses the same WHO 2006 engine as the Ahozon app, and nothing you type leaves this page.

How growth looks at this age

From 10 months to 11 months, the median rises by 0.2 kg. That is a little less than in the month before. The median is now 2.8 times the median at birth. The gap between the 3rd and 97th percentile is 3.8 kg at this age, compared with 1.8 kg at birth, because the curves fan out as children grow. For comparison, the median for girls of the same age is 8.7 kg. Relative to their size, the gap between the girls' and boys' medians is larger now than at birth.

Between nine months and the first birthday the monthly gain is small compared with the early months.

WHO curves, birth to 5 years. Lines show the 3rd, 15th, 50th, 85th and 97th percentiles. The dot marks 11 months.

What does the percentile mean?

A percentile compares a child with healthy children of the same age and sex from the WHO Multicentre Growth Reference Study. At the 40th percentile, 40 out of 100 children weigh less and 60 weigh more. Anything between the 3rd and 97th percentile is in the normal range. What matters most is that a child keeps following a similar curve over time.

How to measure

Weigh your child without clothes or a diaper if you can, on the same scale each time. Home scales can differ from the clinic scale by a few hundred grams.

When to ask your pediatrician

Talk to your pediatrician or child health nurse if a measurement is below the 3rd or above the 97th percentile, or if your child's percentile changes a lot between visits, for example crossing two of the main percentile lines. A single measurement says little; the trend over time matters most.

General information, not medical advice. One measurement says little on its own: talk to your pediatrician or child health nurse about your child's growth.