Real numbers, with sources

Humanity in Charts

A few long-run measures of how human life has changed. Every chart names its source, the date the data was retrieved, and what the numbers cannot tell you. Each has a data table for screen readers and for checking the figures.

How many people have lived on Earth at once: world population, 10,000 BCE to 2023

For most of the last twelve thousand years the human population grew slowly, then climbed steeply after about 1800. The three lines come from different methods, so the picture is best read as a broad shape rather than a precise count.

Limits: Years before 1950 are reconstructions built from archaeology, land-use models and scattered censuses, and the source publishes no error ranges. Our World in Data warns that breaks can occur where one source hands over to another (around 1800 and 1950). Only selected years are plotted, so short-lived dips and rises between them are not visible. Our World in Data states that its World values are HYDE before 1800, sums of available countries for 1800 to 1950, and UN estimates after 1950.

Source: Our World in Data, Population (HYDE v3.3, Gapminder v7, UN World Population Prospects 2024). Retrieved 2026-10-21.

More of the world can read and write: adult literacy rate, 1975 to 2024

The share of adults who can read and write a simple sentence rose from about two in three in 1975 to nearly nine in ten in 2024. That still leaves a meaningful minority of adults without these basic skills.

Limits: This is a global estimate assembled from national censuses and surveys of different dates, with gaps filled by UNESCO modelling, so the smooth yearly path is not a set of direct measurements. The series shows steps in some years (for example 77.3% in 1996 and 79.3% in 1997) that are larger than neighbouring years. We could not confirm from the source pages whether those steps reflect real change or updates to country data or method, so they should not be read as events. The measure captures only basic literacy; it does not show whether people can use reading and writing in everyday life.

Source: UNESCO Institute for Statistics (UIS), via Our World in Data; values cross-checked against the World Bank indicator SE.ADT.LITR.ZS. Retrieved 2026-10-21.

Living longer: world life expectancy at birth, 1770 to 2023

Average life expectancy at birth for the world roughly doubled between the late 1700s and the early 2020s. The series dips around 1959 to 1960 and again in 2020 to 2021, because period life expectancy drops sharply in years with unusually high mortality.

Limits: Period life expectancy is a snapshot of one year's death rates applied to a newborn, not a forecast of any person's lifespan, and it falls sharply in crisis years. Before 1950 only a rough world-level estimate by one researcher exists, and no values are shown for 1914 to 1949, so the two lines are deliberately not joined. UN estimates rely on censuses and registration data, and for some countries the latest census is more than a decade old. Newer UN releases revise earlier years: the World Bank's world series, which uses a different UN edition, gives 50.94 for 1960 instead of 47.82, so the two should not be compared directly.

Source: Our World in Data, Life expectancy (James C. Riley 2005 for years before 1950; UN World Population Prospects 2024 from 1950). Retrieved 2026-10-21.

Getting online: share of people using the Internet, by world region, 2005 to 2024

Internet use rose in every region shown, but starting points and speeds differ widely. By 2024 the share of people online ranged from roughly one in three in Sub-Saharan Africa to more than nine in ten in North America.

Limits: Regional figures are World Bank aggregates of country values that the ITU gathers from national surveys, operator data and its own estimates, so they mix measurement methods and countries update on different schedules. Some series change abruptly (North America 2015 to 2016, South Asia 2019 to 2020), which may reflect revised country data or methods rather than sudden real change; the source pages we read do not explain these steps. The indicator counts people who used the Internet recently, not the quality, speed or purpose of use. Aggregates for Middle East, North Africa, Afghanistan & Pakistan (61.5% in 2024) and the world (71.2% in 2024) were retrieved but are not plotted.

Source: International Telecommunication Union (ITU) World Telecommunication/ICT Indicators Database, via World Bank indicator IT.NET.USER.ZS (regional aggregates). Retrieved 2026-10-21.

Reading charts carefully

Long-run series mix measured data with reconstructions. Where a chart marks values as estimates, treat the exact figure as a best guess with a wide margin, especially before the twentieth century. A line that looks smooth may join sources that count things differently; the notes under each chart say when that happens.