Projections have been revised downwards to reflect the recent sharp fall in net migration.
The UK population is projected to grow at a slower rate over the next few decades than previously reported due to lower levels of migration, before starting to fall in the mid-2050s.
Some 1.7 million people are projected to join the population between 2024 and 2034, pushing the total up 2.5% from 69.3 million to 71.0 million, according to the Office for National Statistics (ONS).
This is smaller than the increase included in ONS figures published last year, which projected a rise of 3.0 million over the same period and the population jumping 4.3% to hit the higher total of 72.2 million by 2034.
The projections have been revised downwards to reflect the recent sharp fall in net migration, as well as lower fertility rates in the future.
UK population growth is projected to slow even further during the 2030s and 2040s, before peaking at 72.5 million in 2054 and then going into decline.
Previous projections suggested the population would continue to grow until 2096.
Net migration is expected to be the only driver of population growth in the UK over the next few decades.
Natural change is projected to turn negative, with deaths outnumbering births each year from 2026 onwards.
James Robards, ONS head of household and population projections, said: “Our latest projections indicate slower population growth than previously projected.
“This is mainly due to lower migration assumptions – reflective of the recent steep fall in net migration – and lower fertility assumptions.
“At the UK level, the population is projected to peak in the 2050s before decreasing.”
Projections are not forecasts or predictions and do not take into account what may or may not happen in the future.
They are instead based on current and past trends, and as those trends change, the projections are adjusted accordingly.
Net migration to the UK – the difference between the number of people moving long-term to the country and the number of leaving – stood at an estimated 204,000 in the year to June 2025, down 69% from 649,000 in the previous 12 months.
An additional 2.2 million people are projected to be added to the population through net migration in the 10 years to 2034, while natural change will see 450,000 more deaths than births, resulting in the overall growth projection for this period of 1.7 million.
The ONS figures suggest the population will peak at different times in the four countries of the UK.
While England is projected to see a peak of 62.1 million people in 2056, the peak is likely to come much sooner elsewhere, arriving in 2035 in Wales (3.2 million), 2033 in Scotland (5.6 million) and 2031 in Northern Ireland (1.9 million).
The figures also reflect the ongoing shift in the age structure of the UK population.
The number of people of pensionable age is projected to rise from 12.4 million to 14.2 million by 2034, when it will account for one in five (20.0%) of the total population.
In contrast, children under the age of 16 will make up a smaller proportion of the population, down from 12.6 million (18.2% of the total) to 11.0 million (15.5%).
By the time the UK population is projected to peak in 2054, pensioners will account for 22.0% of the total and under-16s will make up 14.5%.
Beyond 2054, the population projection falls from 72.5 million to 72.1 million by 2064 and 71.4 million in 2074.
