Population Estimates
UK population grows to 61.8 million

Population: by gender and age, mid-2009

The estimated resident population of the UK was 61,792,000 in mid-2009, up by 394,000 on the previous year. Children aged under 16 represented approximately one in five of the total population, around the same proportion as those of retirement age. In mid-2009 the average age of the population was 39.5 years, up from 37.3 in 1999.

The diagram above is a representation of the age and sex structure of the population, known as a population pyramid. Each bar represents a particular single year of age and the length shows the population of that age. The structure of the pyramid is determined by births, deaths and international migration.

Up to the age of around 70, the number of males and females are fairly equal. At older ages, towards the top of the pyramid, females outnumber males. This is shown by longer bars on the female side of the pyramid. The ratio of females to males increases progressively from 1.1 at age 70, to 2.1 by the age of 89. This reflects the higher life expectancy of women at older ages and higher male mortality during the Second World War. The population pyramid stops at age 89, causing the top of the pyramid to be flat.

Further down the pyramid, people of working age (aged 16 to 64 for males and 16 to 59 for females) represent 62 per cent of the total mid-2009 population. Between ages 37 and 50 there is a ‘bulge’ due to the ‘baby boom’ years of the 1960s and early 1970s.

A sharp narrowing of the pyramid for people aged 30 to 34 reflects the low fertility in the late 1970s. A further narrowing of the pyramid appears between the ages of 5 and 10 reflecting the low fertility rates in the early 2000s. The broadening of the base of the pyramid is due to increasing numbers of births from mid-2002 onwards, reaching just under 790,000 in the year to mid-2009.

Sources: Office for National Statistics, General Register Office for Scotland, Northern Ireland Statistics & Research Agency.

Notes: Estimates of the Very Elderly (those aged 90 and above) for mid-2009 will be published later in 2010.

People of ‘retirement age’ are those aged 65 and over for males and 60 and over for females.

Average age – the median age has been used here which means half the population are older and half the population are younger.

Revised mid-2002 to mid-2008 population estimates for England and Wales were published on 13 May 2010.