57 Million and Rising: How Many People Live With Dementia, Now and in Future

The World Health Organization estimates that 57 million people were living with dementia worldwide in 2021^[1], and every projection reviewed here expects the number to keep rising for decades as populations grow and age. But the same research also finds something more hopeful: in several high-income countries, the chance of developing dementia at any given age has fallen, and how far projections rise depends heavily on whether that continues^[2][3].

Behind every estimate is a household: a person living with dementia, and usually a partner, son, daughter or friend learning to support them. Planners use these numbers to decide how many memory assessments, care workers and care-home places a country will need. This article explains how many people are thought to live with dementia, how those figures are made, and why respected models can disagree by hundreds of thousands of people.

Tens of millions of people live with dementia worldwide, and the number is set to grow

WHO's fact sheet, updated in July 2026, puts the global figure at 57 million people in 2021, with nearly 10 million new cases every year^[1]. Women also provide 70% of the hours of care that people living with dementia receive^[1].

Looking forward, the figures depend on who made them and when. In 2021 WHO estimated that more than 55 million people were living with dementia — 8.1% of women and 5.4% of men over 65 — rising to 78 million by 2030 and 139 million by 2050^[4]. The Global Burden of Disease (GBD) forecasting group, writing in 2022, estimated 57.4 million people in 2019 (uncertainty interval 50.4 to 65.1 million) and forecast 152.8 million in 2050 (130.8 to 175.9 million)^[5]. Alzheimer's Disease International's World Alzheimer Report 2015 put the figure at over 46 million in 2015 and projected 131.5 million by 2050^[6].

These are not three points on one trend: they use different studies, methods and base years. What they share is the direction. In the GBD forecasts, the rise in numbers comes almost entirely from population growth and population aging; global age-standardised prevalence — the share of people with dementia once differences in age structure are removed — stays essentially flat between 2019 and 2050 (a change of 0.1%)^[5].

The growth is far from even. GBD projects the smallest percentage increases in high-income Asia Pacific (53%) and western Europe (74%), and the largest in north Africa and the Middle East (367%) and eastern sub-Saharan Africa (357%)^[5]. Population growth drives most of the increase in sub-Saharan Africa, and population aging most of it in east Asia^[5]. GBD also estimated that there were 1.69 women with dementia for every man in 2019, a pattern expected to continue^[5]. See also our international comparison.

Estimates come from assessing samples of the population, not from counting diagnoses

Many people living with dementia have never been diagnosed, so national estimates come from population studies: researchers assess a representative sample of older people, calculate the share with dementia in each age and sex group, and apply those rates to the national population.

The UK's main source of such rates is the Cognitive Function and Ageing Studies. Between 1989 and 1994, CFAS I interviewed people aged 65 and over in defined areas of England and Wales; between 2008 and 2011, CFAS II went back to three of them — Cambridgeshire, Newcastle and Nottingham — with the same sampling and diagnostic methods, interviewing 7,796 people^[2]. Applying the early-1990s rates to the 2011 population predicted that 8.3% of people aged 65 and over, 884,000 people in the UK, would have dementia; CFAS II found 6.5%, or 670,000^[2]. That is 214,000 fewer than population aging alone would have predicted, and the authors read it as evidence that later-born generations have a lower risk at the same age^[2]. The picture was not better everywhere: among people living in care settings, the share with dementia rose from 56% to 70%^[2].

CFAS II also underpins England's official diagnosis rate. NHS England's monthly figures compare recorded diagnoses with an expected number calculated from CFAS II age- and sex-specific prevalence rates for people aged 65 and over, by five-year age band; the methodology states that these reference rates "remain static"^[7]. On 30 June 2026, 516,230 people had a recorded dementia diagnosis in England, and 66.2% of people aged 65 and over estimated to have dementia had a diagnosis on record^[8]. Any change in age-specific risk since 2008–2011 is not reflected in that denominator. We look at the diagnosis rate in detail in our article on diagnosis rates.

Other countries use the same method. China's national study assessed 46,011 adults aged 60 and over in 2015–2018 and estimated age- and sex-adjusted prevalence at 6.0%, or 15.07 million people^[9]. In India, the Longitudinal Aging Study in India estimated prevalence among adults aged 60 and over at 7.4%, about 8.8 million people, in 2018–2020^[10]. In the US, a widely used estimate put the US Census-adjusted prevalence of clinical Alzheimer's dementia at 11.3% in 2020, about 6.07 million people^[11]; the Alzheimer's Association's 2026 report gives 7.4 million Americans aged 65 and over living with Alzheimer's in 2026^[12]. The US figures cover Alzheimer's dementia only, and the Chinese and Indian figures start at age 60, so these percentages are not comparable.

In many high-income countries, the risk at any given age has fallen

Incidence — the rate of new cases — is the best guide to whether risk is changing. CFAS found a 20% drop in incidence over two decades (95% confidence interval 0–40%), driven by a reduction among men, and estimated about 209,600 new cases a year in the UK^[13]. Pooling seven population cohorts in Europe and the US, the Alzheimer Cohorts Consortium found that the incidence rate fell by 13% per calendar decade between 1988 and 2015, more in men (24%) than in women (8%)^[3]. In the US Framingham Heart Study, the five-year incidence of dementia fell by 44% between the late 1970s and early 1980s and the late 2000s and early 2010s, a fall seen only among people with at least a high school diploma^[14].

Prevalence studies point the same way. In the US Health and Retirement Study, dementia prevalence among people aged 65 and over fell from 11.6% in 2000 to 8.8% in 2012^[15]; a later analysis of the same survey with a different model found age-adjusted prevalence fell from 12.2% in 2000 to 8.5% in 2016, a decline of 30.1%^[16]. In both, rising education was associated with part of the decline^[15][16]. In Denmark's national registers, covering 2 million residents aged 65 and over, age- and sex-adjusted incidence of diagnosed dementia rose about 9% a year from 1996 to 2003, then fell about 2% a year, while total prevalence kept rising^[17].

Different designs, age ranges and definitions: not directly comparable.

Not every study shows a steady decline. In the Hisayama Study of one Japanese town, crude prevalence among residents aged 65 and over rose from 6.7% in 1985 to 17.9% in 2012, then fell to 12.1% by 2022; age- and sex-adjusted incidence rose between cohorts starting in 1988 and 2002, then fell between the 2002 and 2012 cohorts^[19]. Part of the earlier rise in prevalence may reflect longer survival: five-year survival after onset rose from 47.3% to 65.2% between the first two cohorts^[19].

The reasons for falling risk are not settled. Researchers point to more education and better management of cardiovascular risk, high blood pressure and diabetes^[15][14][19], but no single factor explains the trends^[14], and almost all of this evidence comes from high-income countries. On what may reduce risk, see our article on risk factors.

Projections differ because their assumptions differ: the UK as a worked case

Every projection combines a forecast of the population by age with an assumption about the rate of dementia at each age in future. The rates are where models part company, and the UK, with several published models, shows how much that matters.

• CPEC, London School of Economics (2019), for Alzheimer's Society. Estimated almost 885,000 people aged 65 and over living with dementia in the UK in 2019 (748,000 of them in England) rising by 80% to around 1.6 million in 2040^[20]. Its rates vary over time in line with the PACSim simulation model and are assumed to be the same, by age, sex and education, in all four UK nations; it also assumes no disease-modifying treatment becomes available^[20].
• Carnall Farrar for Alzheimer's Society (2024). Estimated 982,000 people living with dementia in the UK in 2024, rising to 1.4 million in 2040, by applying age-banded and time-varying rates from the MODEM project to 2020-based population projections for people aged 65 and over^[21]. It assumes the same rates for men and women and across all UK nations and regions^[21].
• Ahmadi-Abhari and colleagues (2017), England and Wales. Using the English Longitudinal Study of Ageing, a survey of adults aged 50 and over, they estimated that incidence fell by 2.7% a year in 2002–2013 and projected about 767,000 people with dementia in 2016, rising to 1,205,000 in 2040 — a 57% increase driven mainly by longer life expectancy^[22]. Without the fall in incidence, the same model projected more than 1.9 million in 2040^[22].
• Chen and colleagues (2023), England and Wales. Extending the same survey to 2019, they found that age- and sex-standardised incidence fell from 10.7 to 8.6 per 1,000 person-years between 2002 and 2010, then rose to 11.3 by 2019^[18]. If that rise continued, they projected 1.7 million people with dementia in England and Wales by 2040, 70% more than previously forecast^[18].

All of these models project more people living with dementia in 2040 than today. They disagree about how many, and much of the gap comes from one assumption: what happens to the risk at each age. A continuing fall in age-specific incidence gives about 1.2 million in England and Wales in 2040; a renewed rise gives about 1.7 million^[22][18]. The UK-wide figures sit between 1.4 and 1.6 million, but cover only people aged 65 and over and use different population projections^[20][21]. Younger people with dementia are left out of most of these models; see our article on young-onset dementia.

Other countries face the same uncertainty. In the US, one model projects 13.85 million people with clinical Alzheimer's dementia in 2060^[11]; the Alzheimer's Association gives a similar 13.8 million people aged 65 and over by 2060, "barring the development of medical breakthroughs"^[12]. The GBD forecasts build in projected trends in education and in three risk factors — high body-mass index, high fasting blood sugar and smoking^[5] — so they too rest on assumptions about how risk will change. A projection is a careful "if", not a prediction.

What the evidence asks of us

• Plan for more people living with dementia, whichever model is right. Every projection reviewed here, global and national, expects the number to grow^{[5][4][20][22]}. The GBD authors offer their country-level estimates to inform national plans^[5]. In 2021 WHO found that only a quarter of countries had a national policy, strategy or plan for supporting people with dementia^[4].
• Keep measuring. England's official expected-prevalence figure still rests on 2008–2011 rates that "remain static"^[7]. The 2023 English evidence that incidence may be rising again^[18] shows why repeated population studies such as CFAS are needed.
• Close the evidence gap outside high-income countries. Most people with dementia live in low- and middle-income countries^[1], where the largest increases are projected^[5], yet nearly all the evidence on changing risk comes from Europe, North America and Japan. The authors of the European and US cohort analysis call for research on whether declines hold in geographically and ethnically diverse populations^[3].
• Treat falling risk as something to protect, not a given. In Framingham, the fall in risk was seen only among people with at least a high school diploma^[14], and in England the post-2008 rise was steeper among people with less education^[18]. Prevention and health policy can widen or narrow that gap.

None of this is a reason for alarm. It is a reason to plan honestly, so that people who will live with dementia in 2040 and 2050 find diagnosis, support and care ready for them.

Language: this piece uses person-first language ("people living with dementia", "people with dementia"), as most dementia organisations and people with lived experience prefer, and uses clinical terms such as "Alzheimer's disease" only where a study, dataset or diagnosis refers to that specific condition.

Why we're publishing this

We compiled this evidence because people living with dementia, their carers and the organisations that support them need trustworthy figures, and an honest account of their uncertainty, when they make the case for services. The case belongs to them; our part is to say plainly what the data show. This article is part of our Dementia & Health research library.

How to read this data

Prevalence is the share or number of people living with dementia at one time; incidence is the rate of new cases. Most figures here are modelled estimates from population studies that assessed samples of older people, not counts of diagnoses. Danish and NHS England figures count diagnoses only. Studies differ in age range, case definition and whether they cover all dementia or Alzheimer's dementia only, so their percentages are not directly comparable. Age-standardised rates remove differences in age structure; crude rates do not. Every projection rests on assumptions about future risk, population and care. The CPEC and Carnall Farrar projections cover people aged 65 and over; the two England and Wales models rest on survey data on adults aged 50 and over. Evidence on trends is much thinner for low- and middle-income countries.

Use this data

Free to cite with attribution to Understanding Aging. Charities, carers' groups, campaigners and journalists are welcome to reuse these figures and charts. For the underlying figures as a spreadsheet, get in touch.

Important: This article summarises published research and statistics for general information. It is not medical, care or financial advice and cannot be used to diagnose, treat or predict anything about an individual. If you have concerns about your own or someone else's memory or health, please speak to a GP or another qualified health professional.

Sources

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