London: Population Changes, Density and Migration Patterns


Introduction: The People

Analysing population density, migration patterns, median age, and income can help you to make data-driven decisions about the type of properties that people living across different boroughs need.

We’ve drilled into some of the recent data from the Office of National Statistics so that you don’t have to.


Population Change and Population Density

Based on 2021’s census data, unsurprisingly, London is the region with the highest population in the country with 8,799,730 people living within the Capital – this is broken down into 3,077,985 people living in Inner London and 5,721,745 living in Outer London. 

From 2011-2021 the average population increase across the UK was 6.37%, London’s overall population increased by 7.26% with Outer London driving this increase, seeing the highest jump of 8.49%. 

Inner London’s population growth was slightly below the national average at 5.03%. But over the next 10 years, it is expected to see the most significant increase – the population is projected to grow by 15.84%. 

When compared to Outer London’s predicted 10-year growth (2.51%), we can see how the amount of new development lined up within the inner boroughs over the next ten years is expected to shape the population in this area over the coming decade. 

Overall, London’s population is set to grow 7.17% for this time period and is expected to total 9,431,094 people by 2031.

Population density data adds more colour to these population predictions. London as a whole has an average density of 5,596 people per square kilometer (sq. km). Outer London has a population density of 4,502 people per and Inner London has 10,260 people per sq. km. 

When we zoom in a bit and look at population growth and density on a borough-by-borough basis we see some interesting trends and outliers emerge. 

Croydon was the borough with the highest population (390,700), but Tower Hamlets is the most densely populated borough (15,794). 

Camden has the most interesting story to tell in terms of population change. From 2011 to 2021, the population decreased by 4.5% over the decade up to the last census but from 2021 to 2031, the population  is set to increase by 41.9% – the biggest increase predicted across any of the London boroughs. 

Conversely, in Ealing, the population is predicted to decline by 8.7% between 2021 and 2031, this is despite a recorded population growth of 8.2% between 2011 to 2021.

Despite Tower Hamlets being the most densely populated borough, they’ve seen the steadiest population rise (and predicted rise). From 2011 to 2021, the population increased by 21.2% and then is projected to grow by 22.2% in the next 10-year period. 

At the other end of the scale, the City of London has the lowest overall population, (8,595) and Bromley - the largest borough by area - has the lowest population density at just 2,197 people per sq. km, partially due to being 60% Green Belt or Metropolitan Open Land.

Migration Patterns

As is typical of a capital city, London sees a lot of migration, both in and out. 2021’s census data showed that net internal migration (those moving from another local authority in the UK) had much more of an impact on population stats than net external migration (those moving from overseas). 

London’s total net internal migration was -22,310 people (-18,795 for Outer London and -3,515 for Inner London). When compared to the positive, but much less significant net external migration of 650 people (574 for Outer London and 76 for Inner London), this shows that, over the 10 years to 2021, London was acting as a draw to people wanting to move to the UK from overseas, but that people were leaving London to live in other parts of the UK in much greater numbers.

Only five boroughs across all of London had positive net internal migration:

  • Tower Hamlets: 973 people
  • Westminster: 432 people
  • Kensington and Chelsea: 367 people
  • Wandsworth: 49 people
  • City of London: 14 people


Tower Hamlets also saw the second highest net external migration (76) which helps contribute to why it’s one of the most densely populated neighborhoods as it’s popular for both domestic and international migration. 

Newham saw the highest net external migration (153), but one of the lowest net internal migration figures (-1,695). 


Larger cities tend to have a lower median age as young people are drawn there by job opportunities and a faster pace of life.

The median age for London in 2021 was 35.9, a 6.21% increase from 2011. But there’s quite a wide range when we look at it on an individual borough basis. Looking at this data can help indicate the different housing needs that may be required in that borough – as different demographics often have different property requirements. 

Tower Hamlets had the youngest median age (30.74), followed by Newham (32.61), and Hackney (32.76). These three boroughs are geographically next to each other in North East London and have a high population density. 

Whereas, Richmond upon Thames had the highest median age (41.83), followed by Bromley (41.33), and Sutton (39.6). All three of these boroughs with the highest median age are situated in the South of London near large green spaces, contributing to their less dense population. 

Richmond upon Thames also saw the biggest increase in median age – jumping up 3.39 years between 2011 and 2021.

City of London and Havering are the only two boroughs with a population that got younger for this time period – decreasing by 2.77 and 1.5 years respectively. 


Adding income data into the demographic mix can help provide more detail on the type of housing that is needed here – and, when combined with information on average house prices,  whether it is likely to be affordable for people already living in the area.  

London’s median income for 2022 was £39,391 – a 40.68% increase from 2012. When comparing this to the South East’s income growth for the same period (21%), we can see just how considerable a jump this has been. 

Inner London had a higher median income at £40,812 than Outer London at £38,453 but had a smaller percentage increase from 2012 to 2022. 

Out of all the boroughs, Wandsworth had the highest median income in 2022 at £47,901 – a significant 28.8% increase from 2012. 

Four out of the five highest-earning boroughs are in South London: Wandsworth, Richmond upon Thames, Kingston upon Thames, and Bromley. 

There’s also a close geographical grouping between the lowest median income boroughs. Three of the bottom five are neighbouring boroughs in East London. 

Barking and Dagenham had the lowest median income in London in 2022 at £33,454 but saw substantial growth since 2012 of 24%. 

Waltham Forest saw the biggest increase in median income since 2012 of 37.9% – growing from £29,018 to £40,003 in 10 years. 

Harrow (33.2%), Newham (30.4%), and Bexley (29%) also saw major increases in median income for the same time-period. 

Kensington and Chelsea was the only borough that saw a decline in median income – decreasing 0.4% from £41,047 to £40,868.

Related Resources

If you've enjoyed the data insights about demographics in London, check out our other  reports for the region below: