How Common Is Dyslexia?
Researchers disagree. Some say as many as one child in five has dyslexia. Many others put it at about 5 to 10 in every 100 students. The two views draw the line in different places (Catts and colleagues, 2026). Another figure you may see is for some of the symptoms, not dyslexia.
Why do the numbers differ?
Dyslexia is a name for a pattern of trouble reading words, spelling, or both. Struggling to read says nothing about how smart your child is.
The International Dyslexia Association (IDA) wrote a new definition in 2025. It puts the trouble "along a continuum of severity". In our view, there is no natural line on it with dyslexia on one side. Catts and colleagues (2026) report a disagreement about where that line belongs. In our view, where the line goes is a choice made against a standard.
In our view, any count of dyslexia moves with where that line is drawn.
Researchers disagree about how common dyslexia is (Catts and colleagues, 2026). Some say as many as one child in five has it (Shaywitz and colleagues, 2021, as reported in Catts and colleagues, 2026). Many others see dyslexia as a more severe condition. They put it at about 5 to 10 in every 100 students (Fletcher and colleagues, 2019, as reported in Catts and colleagues, 2026). The two views draw the line in different places.
Common questions from parents
Do researchers agree that one child in five has dyslexia?
Researchers disagree about how common dyslexia is (Catts and colleagues, 2026). Some say as many as one child in five has it (Shaywitz and colleagues, 2021, as reported in Catts and colleagues, 2026). Many others see dyslexia as a more severe condition. They put it at about 5 to 10 in every 100 students (Fletcher and colleagues, 2019, as reported in Catts and colleagues, 2026). The two views draw the line in different places. In our view, any count of dyslexia moves with where that line is drawn.
Where does the figure for some of the symptoms come from?
You may see 15 to 20 in every 100 people. That figure comes from the International Dyslexia Association (IDA). It is for people with some of the symptoms of dyslexia. The IDA says perhaps as many as that. That figure is not a count of people who have dyslexia.
Does it matter how common it is for my child?
Each figure on this page is about a large group, not one child. In our view, how common it is does not change your next step. That step is to work out which job of reading is going wrong. The exception is a skill that was there and has gone. Our position is that a lost skill goes to a doctor first, not a tutor.