Auckland's population has reached a landmark 1.5 million.

The face of New Zealand is changing and the most drastic changes will take place in Auckland, where projections show that within 10 years, non-Europeans will make up nearly half of the population.

By 2021, for every 100 residents in Auckland, 27 will be Asian, 17 Pacific Islanders, 12 Maori and just 53 will be European - down from 59 today. (Some people identify with two or more ethnicities).

"Auckland has dominated New Zealand's population growth over the last two years, which allows for births, deaths, arrivals and departures of residents," said population statistics manager Andrea Blackburn.


"The 1.5 millionth person could be a migrant coming from overseas, or from within New Zealand, but it is most likely to be a baby, because births add more than net migration to Auckland's population growth."

Ms Blackburn said the city's population hit 500,000 at the 1961 Census but crossed the one million mark by the time of the 1996 Census.

For New Zealand as a whole, Europeans will still make up 71 per cent of the population in 2021, followed by 16 per cent Maori, 14 per cent Asian and 9 per cent Pacific Islanders.

Associate Professor Elsie Ho, of the University of Auckland's social and community health department, said Auckland was a magnet for Asian immigrants and present immigration policy targeted people who helped increase its population by births.

She said Auckland attracted people of Asian heritage because it offered a metropolitan lifestyle, clean and green environment and good schools.

"Immigration policies favour the young, affluent and qualified - and starting a family or raising a family is why many of them initially choose to come to New Zealand," said Dr Ho.

She said many Asians chose to move to New Zealand for the sake of their children. Chinese, who felt restricted by China's one-child policy, could have more children.

"For new migrants, many would initially like to stay in a place where they have got friends or relatives, and Auckland is also more likely to be able to offer them this compared to other New Zealand cities."

Dr Ho said an increase in mixed marriages meant that in 2021, many Aucklanders would identify with more than just one ethnicity and this was a good thing for building better race relations and cultural understanding.

The Asian population is expected to increase slightly in Wellington and Christchurch over the next 10 years.

In Wellington, it is predicted the European population will dip from 78 to 75 per cent by 2021, while Asians grow from 10 to 12 per cent, and Maori and Pacific remain unchanged at 14 per cent and 9 per cent.

The population of Asians (7 per cent) and Maori (8 per cent) are also predicted to grow slightly in Canterbury over the same period, hitting 9 per cent, while European numbers drop from 88 per cent to 86 per cent.

Statistics New Zealand said fertility rates were higher for Maori and Pacific populations than they were for Europeans and Asians.

Auckland's population ranks fifth largest across Australia and New Zealand, behind Sydney, Melbourne, Brisbane and Perth.