A baby born about 8.45am next Tuesday could well be the 4.5 millionth New Zealander.
Statistics New Zealand's (SNZ) population clock is closing in on the mark, reaching 4,498,742 by mid-afternoon today.
The clock is based on the 2006 census, updated with births, deaths and migration data.
SNZ senior demographer Kim Dunstan said the clock was a good indicator of the country's population.
It was based on population estimates published every quarter, which took into account New Zealand's "very good" demographic data, he said.
The first estimates to be based on the 2013 census would be for the year to the end of June 2014 and would be published next August.
They would include results of a survey that showed how many people had been missed by the 2013 census and how many people might have been counted more than once.
Those temporarily overseas at the time of the census, possibly 70,000 to 80,000 people, would also be included, Dunstan said.
The survey carried out after the 2006 census showed that 98 per cent of the population who should have been counted had been.
After the 2006 census, which came during a period of high immigration, the national population estimate was revised up about 40,000, or 1 per cent.
In 2001, the change was fewer than 20,000.
- Fairfax Media