A country’s place at five does not fix its place at nineteen.
Each line is one country’s average boy, ranked against the other 159 at every age. Tallest at the top. Four are named. Hover or tap any line to name it.
NCD-RisC, Lancet 2020. Year of measurement, ages 5-19. Boys, 2019, 160 countries. Rank within the 160 countries drawn.
Around age eleven, girls are taller than boys in 144 of 160 countries.
Each line is one country: its girls’ average height minus its boys’, at each age. Above the zero line, the girls are taller.
The lead has peaked at eleven or twelve in 99.88% of the 5,205 country-years measured since 1985.
NCD-RisC, Lancet 2020. Year of measurement, ages 5-19. 2019, 160 countries. Rwanda: boys 129.21 cm, girls 139.22 cm at 11.
Adults in every country are taller than those born in 1896, by 0.52 to 20.16 cm.
From here the data is adults, by the year they were born. Each stroke is one country and one sex: from the average height at 18 of people born in 1896 up to those born in 1996.
NCD-RisC, eLife 2016. Year of birth, height at 18. 200 countries, both sexes. Each run is sorted by its own 1896 height. Strokes for the 40 countries with the widest published ranges are drawn and never named.
In 182 of 400 country and sex groups, the tallest generation has already been born.
Each dot is one country and one sex whose average height at 18 has fallen more than 0.5 cm since its tallest birth year: when that generation was born, and how much shorter the 1996 generation is.
NCD-RisC, eLife 2016. Year of birth, height at 18. 200 countries, both sexes. The world average is Our World in Data’s population-weighted aggregate of the same study.
Pick a country. Its average height at 18, for everyone born 1896 to 1996.
Two lines for the country you pick, men and women, born 1896 to 1996. The world average is behind them, and every other country is the faint field.
NCD-RisC, eLife 2016. Year of birth, height at 18. 160 of 200 countries can be picked: those with the narrowest published ranges. World lines: Our World in Data.
Where the numbers come from
The two studies
Both are published by the NCD Risk Factor Collaboration, both are open (CC BY 4.0), and both are modelled national averages rather than measurements of individuals.
- Children, ages 5 to 19. Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019, The Lancet, 2020. Indexed by the year the children were measured. The first three sections use the 2019 numbers.
- Adults, at 18. A century of trends in adult human height, eLife, 2016. Indexed by year of birth, for everyone born 1896 to 1996. The last three sections use it.
The two are never averaged, ranked or subtracted across each other. The world average lines are Our World in Data’s population-weighted aggregates of the 2016 study.
Which countries are named
Every estimate carries a published range, and the ranges are wildly uneven: 1.09 cm for Japan against 16.12 cm for Angola in the same year. A country known only to 16.12 cm cannot carry a ranking. So the 200 countries are sorted by the width of their own range and the widest fifth is set aside: 160 countries are drawn and named, and the 40 widest are drawn but never named. The cutoff is 9.75 cm.
What this page does not say
- Who inside a country got taller. Neither study carries income, education, region or city. The unit is a country, a sex and an age, and there is nothing underneath it.
- That the gap between countries is closing. In centimetres it narrows for boys and widens for girls (16.9 cm at five to 19.4 cm at nineteen). Measured against the children’s own height it narrows for both: boys 26.4% to 13.7%, girls 15.2% to 12.1%.
Reproducing it
One pipeline derives every number on this page from the two published files and asserts each one against a frozen findings record before writing it. If a guard and the record disagree, the build stops. The century lines are decoded from the shipped bytes and checked against that same record, value by value, before they are drawn.