NSW Department of Planning and Environment

A changing population

The growth of NSW

NSW has been growing.

The population of our state changes over time because of births and deaths, as well as overseas and domestic migration (interstate and within NSW).



The NSW projections look at these components of population change and make assumptions about how they will stay the same or vary. This page looks at these patterns and shows how we set assumptions for the future.

How migration influences population

Migration is heavily influenced by age, affecting how likely someone is to move, and how far they move. Most people only move one or 2 suburbs away. There are also certain age groups who are more likely to move than others. These age profiles for migration are used to set migration assumptions, so the age of the population overall affects how many people might move, and who comes or goes in an area. 


Overseas migration

For a person to be counted as an overseas arrival or overseas departure, they must be in the country or overseas for 12 out of 16 months. Overseas migration counts include people coming as permanent residents as well as those who come on temporary resident visas (for example, New Zealanders, students, skilled workers).

NSW has grown from net overseas migration (NOM), which is the balance of thousands of people coming and going each year. The COVID-19 pandemic disrupted overseas migration, and even with people returning, the disruption during 2020 and 2021 will continue to be felt for the next 20 years because of the age profile of people coming and going.


Domestic migration

People moving within Australia are a key driver of population change at a local level. There are some migration corridors that have been in place for decades, and our projections assume these flows will remain in place.

Even when we expect there will be more people moving to a place (for example, because of new housing, or new job opportunities), we assume that the age of people moving (or staying) is about the same.


Explore migration flow

The effect of births

Every baby born is part of NSW’s population growth, and we project the numbers of babies into the future based on 2 things:

  • assumptions about the average number of babies who will be born to all women (the total fertility rate)
  • the number of women who are at parenthood ages (15 to 44)

When there is a population with more women in their 20s and 30s, this translates to more babies. In NSW we’ve seen the numbers of babies born going up, even when the NSW birth rate was going down.

The projections also assume different total birth rates for different parts of NSW, reflecting long-term patterns in the data.


The effect of deaths

 Every death in NSW has a part to play in slowing population growth. We project the effect of people dying based on 2 things:

  • life expectancy at birth which tells us to what ages people are most likely to live
  • the number of people at each age

In Australia, most people will live to older ages. This means where there are more older people, we can expect to see more deaths. But in Australia, life expectancy continues to improve every year. This means we see more people living to older ages compared to 10, 20 or 50 years ago. This growing life span also contributes to population growth.