Population Projection Calculator
Choose a country and enter people, not rates. Set annual births, deaths and net migration, then see the 5–10 year trend, age shape and structure.
Country presets use 2023–2024 public estimates, rounded to the nearest 10,000. Changing the country replaces the four values. All calculations run in the browser; nothing is uploaded or stored.
How the calculator works
Each year, the population is last year's population plus births, minus deaths, plus net migration. Births and deaths are the annual counts you enter, not rates applied to the population. Positive net migration adds people; negative net migration removes them.
P(t+1) = P(t) + births − deaths + net migrationChina example (2026)
Start with 1.40828 billion people, 9.54 million births, 10.93 million deaths and 310,000 net emigration. The annual change is a loss of 1.70 million people. Ten years at that count gives about 1.391 billion in 2036, a fall of 17 million (−1.21%).
| Item | People per year | Note |
|---|---|---|
| Births | +9.54 million | China, 2024 |
| Deaths | −10.93 million | China, 2024 |
| Net migration | −310,000 | UN 2020–2025 annual average estimate |
| Total | −1.70 million | Net change per year |
The example shows the arithmetic only. Real births and deaths change from year to year, and the age structure changes too, so this is not an official forecast.
Reading the three charts
- Trend: year-end population from the start year to the final year. The vertical axis scales to the range of the result, and the start and end values are labelled.
- Shape: a shrinking population is drawn as an inverted pyramid (10, 8, 6, 4, 2 people per row); a growing population is reversed. The rows show direction, not a real age distribution.
- Structure: the share of the population aged 0–14, 15–64 and 65+, converted into people from the starting population. It describes the start year, not the projected year.
China-only data
When China is selected, the page adds the main destinations of Chinese emigrants, the provinces with the highest and lowest birth rates, and the provinces with the highest death rates. Other countries show national totals and age structure; province-level data is not available for them.
Data sources
China: 1.40828 billion at the end of 2024, 9.54 million births and 10.93 million deaths (National Bureau of Statistics). Net migration is the UN World Population Prospects 2024 annual average of about −310,000 for 2020–2025; China does not publish an official series. Provincial birth and death rates are 2023 statistical-communiqué approximations. Emigration stock is from UN international migrant stock and national censuses.
Country presets: UN World Population Prospects 2024 and national statistical offices, 2023–2024 approximations, rounded to the nearest 10,000.
What the model leaves out
- Fixed counts: births, deaths and migration stay at the same annual number. If the population falls, deaths usually do not stay constant.
- Age structure: births come from women of childbearing age, and deaths rise as the population ages. The pie chart shows the start-year structure only.
- Migration shocks: net migration is the least reliable term; study, work and family flows can change sharply from year to year.
- Not a forecast: this is a scenario calculator, not a UN, government or statistical-office projection.
Questions
Why enter people instead of birth and death rates?
Most people know how many babies were born and how many people died in their country, but not the exact rate per 1,000. Entering annual counts avoids a conversion step. If you only have a rate, multiply the population by the rate and divide by 1,000 to get the annual count.
What is the default net migration?
China defaults to 310,000 net emigration per year, the UN 2020–2025 annual average estimate. You can change it: negative for emigration, positive for immigration, or zero to see natural change only.
Which years can I choose?
The start year can be 2026–2035, and the horizon is 5–10 years. The default is 2026 plus 10 years, and the table runs from the start year to the final year.
Why doesn't the pie chart change with the projection?
The preset age structure covers the start year. The model has no age cohorts, so it cannot reliably project future structure. The pie chart describes the starting point, not the result.
How accurate are the country values?
Presets are rounded to the nearest 10,000 and are intended for quick scenarios, not for a paper, policy decision or investment case. For official figures, use the latest UN World Population Prospects or the national statistical office.