Transtasman age gap getting bigger

An international consumer research company predicts we will be the 61st oldest country in the world by 2030 - up 10 places from our current ranking. Photo / File

New Zealand's population is tipped to age at a faster rate than our Australian neighbours, and fertility rates among Kiwi women will drop over the next 15 years as the population pushes past five million.

A new international report offers a glimpse of how New Zealand may look in 2030.

As the country's ageing population continues to grow, an international consumer research company predicts we will be the 61st oldest country in the world by 2030 - up 10 places from our current ranking.

By then, the median age of Kiwis is expected to be 40.1, up from 37.1 last year. The median age for the world's population is projected to hit 33.9 by 2030 - four years older than last year's median age.

The Euromonitor International report used population data from Statistics New Zealand to compare New Zealand to other countries.

More elderly Kiwis over the next 15 years also means our median age will exceed Australia's by about four years. Our counterparts across the Tasman are expected to have a median age of 39.4 in 2030, up from their current median age of 37.4.

Japanese people will continue to live longer lives. Their current median age is 46 - the world's highest - but this is tipped to hit 52.7 by 2030.

Niger, however, records the lowest median age of the world's 196 countries, both last year and in 2030 projections.

In 2013, the west African nation had a median age of just 15. This is expected to rise marginally to 15.2 by 2030.

Meanwhile, the report indicates New Zealand women will have fewer babies in the future. Last year, New Zealand's fertility rate was two children born per female, slightly higher than Australia's rate of 1.9.

At 4.6 children per female, women in the Middle East and Africa had the highest fertility rate, while Eastern European women had the lowest at 1.6.

By 2030, Euromonitor International expects the fertility rate to drop from 2.9 in 2013 to 2.6.

Women in Australia and Eastern Europe are expected to buck the trend, with rates expected to increase to 2 and 1.7 respectively.

The fertility rate in New Zealand, however, is expected to decline to 1.8.

According to Statistics New Zealand, New Zealand's population will jump to 5.2 million by 2030, up from the current 4.5 million.