Natural increase
Births minus deaths in a population, not counting anyone moving in or out.
In short
Natural increase can be positive or negative. When deaths outnumber births, it's called natural decrease. Either way, migration is tracked separately, as net migration.
How it's calculated
Usually reported as a rate: the crude birth rate minus the crude death rate, per 1,000 people per year. A whole-number rate rather than a percentage is the demographic convention.
Natural increase rate = crude birth rate − crude death rate
Typical values
Why it matters here
Natural increase, not migration, is what keeps most of the ridgelines on the canvas climbing. A country can gain or lose people through migration in either direction and still be shaped mostly by whether it adds more people through births than it loses through deaths.
At the global scale, natural increase is the only driver — there is no migration to or from the planet. The world's natural increase rate peaked around 1963 at roughly 22 per 1,000, corresponding to the fastest phase of the 20th-century population boom. It has been falling ever since, and the UN projects it will approach zero by the end of this century as fertility converges toward replacement level worldwide. Detailed crude birth rate and death rate series by country are published in the UN World Population Prospects.
Natural increase vs. total population growth
Population change = natural increase + net migration. In countries with large migrant flows — like Australia, Canada, or the Gulf states — net migration can dwarf natural increase and produce very different total growth. In countries with low and falling fertility, like Japan or Italy, natural decrease is partially or fully offset by immigration. Reading natural increase alone does not tell the full population story, but it remains the demographic foundation underneath every country's trajectory.
Frequently asked questions
What is natural increase in population?
Natural increase is the difference between the number of births and the number of deaths in a population over a given period, not counting migration. It is usually expressed as a rate per 1,000 people per year. A positive value means births outnumber deaths; a negative value — called natural decrease — means the reverse.
How is the natural increase rate calculated?
The natural increase rate equals the crude birth rate minus the crude death rate, both measured per 1,000 people per year. For example, if a country has a birth rate of 20 per 1,000 and a death rate of 8 per 1,000, its natural increase rate is +12 per 1,000.
What is the difference between natural increase and population growth?
Population growth combines natural increase (births minus deaths) with net migration (arrivals minus departures). A country can have negative natural increase but still grow if enough people move in, or can shrink despite positive natural increase if more people leave than arrive. The Our World in Data page on components of population growth breaks down each country's change into its natural increase and migration contributions.
Which countries have negative natural increase?
Several countries in Eastern Europe and East Asia now have negative natural increase. Russia, Japan, South Korea, Germany, and most of the Baltic states have all recorded natural decrease in recent years, driven by low fertility and ageing populations. Our World in Data charts natural population growth rates by country from 1950 to the present.