Skip to main content

How common is dyslexia?

5 minute read · updated October 28, 2026

12 sources: 3 government or law, 3 peer-reviewed research, 6 charity or professional body

There is no single agreed figure, because estimates depend on the definition and cut-off used. A 2025 review reports published rates between about 5% and 20%.[1] The British Dyslexia Association says ten percent of the population are believed to be dyslexic, and SPELD NSW in Australia gives 5 to 10%; neither explains how its figure was estimated.[2][3]

See your own reading experiences in one clear summary.Take the free 8-minute reading check

Prevalence means the share of a population that has a condition at a given time. For dyslexia, the answer depends heavily on the definition used, so this page lists only figures that sources state, and says what each one counts. A population figure says nothing about whether any one person is dyslexic.

Figures published by major organizations

Prevalence figures as stated by each source (read October 2026)
SourceFigureWhat it refers to
Carroll and colleagues, UK Delphi paper (2025)About 5% to 20%The range of published rates, which depend on the cut-off used to define reading disability[1]
British Dyslexia Association, UKTen percentThe share of the population "believed to be dyslexic"; no method given[2]
SPELD NSW, Australia5% to 10%People affected by dyslexia; no method given[3]
International Dyslexia Association, US (2020 fact sheet)6% to 7% of the school populationUS students classified as having a learning disability for special education; about 85% of these have a primary difficulty in reading and language processing[4]
International Dyslexia Association, US (2020 fact sheet)Perhaps as many as 15% to 20%People with some features associated with dyslexia, such as slow or inaccurate reading or poor spelling; not a diagnosis rate[4]

The NHS does not give a figure on its current dyslexia pages; it describes dyslexia as a common learning difficulty.[5]

Why the numbers differ so much

The main reason is that dyslexia has no sharp boundary. The 2025 Delphi panel agreed that dyslexic difficulties exist on a continuum and can be experienced to different degrees of severity.[1] Where a study draws the line, for example below a certain percentile on a reading test, decides how many people fall on the dyslexia side of it.[1]

A 2016 review by Charles Hulme and Margaret Snowling, University of Oxford researchers, makes the same point: reading skill is spread continuously across the population, so any diagnostic cut-off is partly arbitrary.[6] It notes that a widely used threshold, reading accuracy more than 1.5 standard deviations below average, identifies roughly 7% of the population.[6] Move the line and the percentage moves with it.

The Delphi authors note that some researchers, including Wagner and colleagues, argue prevalence is better described as a distribution of severity than as a single number, and that "unexpectedly" poor readers can be found at all levels of reading ability.[1] The IDA figures above also measure different things: one counts students classified for special education services, the other estimates how many people have some related features.[4]

Definitions behind the figures

Definitions also changed in 2025. The BDA adopted the UK Delphi definition, and the International Dyslexia Association released its first revised definition since 2002.[11][12] Clinical manuals use their own terms: DSM-5 uses specific learning disorder in reading and ICD-11 uses developmental learning disorder with impairment in reading (the manuals' terms), each with its own criteria.[1] A study using one definition will not count exactly the same people as a study using another.

Co-occurring conditions add another layer. The Delphi panel agreed that dyslexia frequently occurs alongside developmental language disorder, dyscalculia, ADHD and developmental coordination disorder (the panel's terms).[1] For overlap figures, see dyslexia and ADHD in adults and does dyslexia affect math.

Quick answers

Is it true that 1 in 10 people have dyslexia?

The BDA says ten percent of the population are believed to be dyslexic, without saying how that was estimated.[2] Published research rates range from about 5% to 20% depending on the cut-off.[1]

Why do some sources say 20%?

The IDA estimates that perhaps as many as 15% to 20% of people have some features associated with dyslexia, which is broader than a diagnosis rate.[4]

How many adults have undiagnosed dyslexia?

No source reviewed here gives a figure. The BDA says many people are undiagnosed, partly because of the cost of assessment.[8]

Is dyslexia the most common learning difficulty?

SPELD NSW describes it as the most common learning difficulty, and the NHS calls it a common learning difficulty.[3][5]

Review status

Source-checked, not expert-reviewed

Drafted with AI assistance. Each factual claim was checked against the source it links to on 2026-10-28. No clinician, psychologist or dyslexia specialist has reviewed this page. See the claims register.

Sources

  1. [1]Toward a consensus on dyslexia: findings from a Delphi study. Carroll, Holden, Kirby, Thompson, Snowling and the Dyslexia Delphi Panel. Journal of Child Psychology and Psychiatry (doi:10.1111/jcpp.14123), 2025. Accessed 2026-10-28. Peer-reviewed research
  2. [2]Dyslexia. British Dyslexia Association. Accessed 2026-10-28. Charity or professional body
  3. [3]Identification of specific learning difficulties. SPELD NSW. Accessed 2026-10-28. Charity or professional body
  4. [4]Dyslexia basics (Internet Archive snapshot of 2026-10-09). International Dyslexia Association, 2020. Accessed 2026-10-28. Charity or professional body
  5. [5]Dyslexia. NHS (England). Accessed 2026-10-28. Government or law
  6. [6]Reading disorders and dyslexia. Hulme and Snowling. Current Opinion in Pediatrics 28(6): 731-735, 2016. Accessed 2026-10-29. Peer-reviewed research
  7. [7]Towards a consensus for dyslexia practice: findings of a Delphi study on assessment and identification. Holden, Kirby, Snowling, Thompson and Carroll. Dyslexia 31(1): e1800 (doi:10.1002/dys.1800), 2025. Accessed 2026-10-28. Peer-reviewed research
  8. [8]Dyslexia friendly workplaces: a guide for employers. British Dyslexia Association, 2023. Accessed 2026-10-28. Charity or professional body
  9. [9]Highlights of the 2023 U.S. PIAAC results (NCES 2024-202). National Center for Education Statistics, U.S. Department of Education, 2024. Accessed 2026-10-29. Government or law
  10. [10]What PIAAC measures. National Center for Education Statistics, U.S. Department of Education. Accessed 2026-10-29. Government or law
  11. [11]Dyslexia Delphi study papers have now been finalised. British Dyslexia Association, 2025. Accessed 2026-10-28. Charity or professional body
  12. [12]IDA's new definition of dyslexia. LD@school (Learning Disabilities Association of Ontario), 2025. Accessed 2026-10-28. Charity or professional body

Related reading

Which reading situations come up most for you?

Find out in 8 minutes. Free, no sign-up, skip any question. Your answers stay in your browser.

Start the free reading check

This educational questionnaire summarizes what you tell us about reading and writing. It does not screen for, diagnose, or rule out dyslexia or any other condition.