An ageing country: people and long-term spending
By 2075 there are 43.1 people over pension age for every 100 of working age in the ONS principal projection, up from 28.0 in 2024. In the OBR's baseline, spending that rises with age goes from 26.3% of GDP in 2025-26 to 34.5% in 2075-76.
Assumptions
Each switch picks a projection the ONS has published. We do not make our own.
Neither the ONS nor the OBR publishes a projection with a different state pension age, so there is nothing to switch to. The ONS projections follow the law as it stands; the OBR baseline follows the government's stated plan.
The pension ages the ONS projections use
Children under 16, working age, and pensionable age populations are based on State Pension Age (SPA) for a given year. Women's SPA increased to 65 between April 2016 and November 2018. From December 2018, the SPA for both sexes increased to 66 by October 2020 (Pensions Act 2011). Between 2026 and 2028, the SPA will increase from 66 to 67 years for both sexes (Pensions Act 2014), and will increase to 68 between 2044 and 2046 (Pensions Act 2007).
People over pension age for every 100 people of working age
43.1 in 2075 in the principal projection, from 28.0 in 2024. Variants range from 33.0 to 55.8.
- ONS principal projection
- Range of ONS high and low variants
People of working age for each person over pension age
2.3 in 2075 in the principal projection, from 3.6 in 2024. Variants range from 1.8 to 3.0.
- ONS principal projection
- Range of ONS high and low variants
Births and deaths each year
652,000 births and 648,000 deaths in the year to mid-2025. In the principal projection deaths outnumber births from 2026, and by 2075 there are 869,000 deaths to 557,000 births.
- Births
- Deaths
- Range of ONS high and low variants
Left of the dotted line: ONS estimates. Right of it: ONS projections.SourcedSourcedONS mid-year estimates: UK births in the year to 30 June.ONS Population estimates for the UK: components of population change (table MYEB5)
Spending that rises with age, % of GDP
34.5% of GDP in 2075-76 in the OBR baseline, from 26.3% in 2025-26. OBR scenarios range from 29.9% to 37.7%.
- OBR baseline
- Range of OBR scenarios
The OBR breaks spending down for these years only.
What age-related spending is made of, OBR baseline
| % of GDP | 2025-26 | 2075-76 |
|---|---|---|
| Health | 8.3% | 13.5% |
| Adult social care | 1.2% | 1.8% |
| Education | 4.5% | 3.4% |
| State pension | 4.8% | 8.6% |
| Other welfare | 6.1% | 6.4% |
| Public service pensions | 1.4% | 0.9% |
| OBR baseline | 26.3% | 34.5% |
What this page shows
How the UK's population is projected to age, and what that means for public spending. The first three charts come from the ONS national population projections: its principal projection and 13 variants. The last comes from the OBR's long-term projections of public spending, its baseline and 6 other scenarios.
Every chart is a range, never a single line: the shaded band runs from the lowest to the highest published variant or scenario, and the solid line is the official central case.
How it works
The ONS projects the population from assumptions about how many children people have, how long they live and how many people move to and from the UK. Its variants change one assumption at a time, plus a few combinations. The switches above pick one of them; when the ONS has not published a mix, the page says so instead of making one up.
The OBR builds its spending projections on the ONS principal projection, and publishes scenarios with other assumptions about population, health and how pensions and benefits rise. Two figures are worked out here from published numbers, and are marked Estimate with the method: people of working age per person over pension age, and spending in an OBR scenario (the OBR baseline plus the change the scenario makes).
Questions
Are these forecasts?
No. They are projections: what happens if assumptions about births, deaths and migration hold. The ONS publishes a principal projection and variants with higher or lower assumptions. We show them all and make none of our own.
Why does an ageing population matter for public money?
Spending on health, care and the state pension rises with age, while most tax is paid by people of working age. In the OBR's baseline, spending that rises with age goes from 26.3% of GDP in 2025-26 to 34.5% in 2075-76.
Who decides the state pension age?
The government, through Parliament. The ONS projections follow the law as it stands; the OBR's baseline follows the government's stated plan. Neither publishes a projection with a different pension age, so this page has no switch for it.
Is “people of working age per person over pension age” the number of workers?
No. It counts everyone aged 16 up to state pension age and divides by everyone at or over it. Some people of working age do not work and some people over pension age do. We work it out from the ONS projection counts and mark it as an estimate.
Sources and editions
- OBR Fiscal risks and sustainability – July 2026Office for Budget Responsibility, published 7 Jul 2026. Edition used: FRS-2026-07. OGL v3.
- ONS Population estimates for the UK: components of population change (table MYEB5)ONS, published 1 Oct 2026. Edition used: MYEB-2026-10-01. OGL v3.
- ONS National population projections: 2024-based (UK principal and variant projections)ONS, published 28 Apr 2026. Edition used: NPP-2024based-2026-04-28. OGL v3.
- SourcedTaken from an official release, linked.
- EstimateDerived or scaled from official figures; the method is shown.
- Hover over or focus a number to see its method and source.
Assumptions about fertility, migration and life expectancy are driven by population change; the state pension age and how pensions and benefits rise are set by the government.