At what age can a child's IQ be tested?
Tests exist for very young children. The WPPSI-IV covers ages 2 years 6 months to 7 years 7 months, and the Stanford-Binet 5 starts at age 2. But scores in the preschool years are much less stable than later ones. A 4-year-old's result can shift by 10 points or more by the time the child is 8, because development at that age happens in uneven spurts and young children's attention and cooperation vary from day to day.
From around 6 to 8, scores become reasonably stable, and in adolescence they predict adult scores fairly well. For that reason most psychologists advise against testing young children simply out of curiosity. Testing is useful when there is a question to answer: is this child struggling for a reason, or ready for more challenge than school offers?
How real IQ testing works for children
A proper assessment is carried out one to one by an educational or clinical psychologist. For school-age children the most widely used test is the WISC-V. It takes about an hour to an hour and a half and includes puzzles with blocks, pattern grids, vocabulary questions, memory tasks and speed tasks. Children usually experience it as a series of games.
The psychologist scores each subtest against children of exactly the same age, in bands of a few months, and writes a report. A good report does not stop at a single IQ number. It describes the profile across verbal comprehension, visual-spatial ability, fluid reasoning, working memory and processing speed, because the pattern often matters more than the total: a child with strong reasoning but slow processing speed needs different support from a child who is slower across the board.
Assessments can be arranged through the school, through health services when there is a clinical concern, or privately. Private assessments are expensive, so ask what the report will include and how it will be used before you book.
What online tests can and cannot tell you
An IQ score is a comparison with people of the same age. A test normed on adults compares your child with adults, which makes the number meaningless. Online "IQ tests for kids" rarely say how, or whether, they were normed on children at all, and none of them can observe how a child approaches problems, which is a large part of a professional assessment.
Online puzzles can be fun and harmless, and they give children practice with logic. They cannot identify giftedness, a learning difficulty, ADHD or autism, and a high or low number from one should not shape decisions about schooling. The tests on this site are built and normed for adults; we do not offer a score for children.
Giftedness and gifted programmes
There is no single definition of gifted. Many programmes use an IQ of around 130 (the top 2%) as a guide, some use 125, and many no longer rely on IQ alone. Schools often combine group ability tests, achievement results, teacher observations and portfolios of work. In the United States many districts screen with group tests such as the CogAT or NNAT and then test individually; in the UK, schools commonly use group tests such as CAT4 and identify the most able pupils as part of normal teaching.
Signs that a child may be highly able include learning to read early, an unusual vocabulary, intense curiosity, a long attention span for things that interest them and frustration with work that is too easy. None of these is proof, and many able children show few of them.
When to ask the school
- Your child is struggling with reading, writing or maths despite real effort and good teaching.
- Your child is consistently bored, finishes work far ahead of others or is losing motivation.
- Teachers have noticed problems with attention, memory or following instructions.
- There is a big gap between how bright your child seems in conversation and how they perform on schoolwork.
Start with the class teacher, then the school's special educational needs coordinator (SENCO in the UK) or school psychologist. They can arrange or advise on a proper assessment and explain what support follows from it.
Sources
Wechsler, D. WISC-V Technical and Interpretive Manual. Pearson, 2014.
Wechsler, D. WPPSI-IV Technical and Interpretive Manual. Pearson, 2012.
Roid, G. H. Stanford-Binet Intelligence Scales, Fifth Edition: Technical Manual. Riverside Publishing, 2003.
Flanagan, D. P. and Alfonso, V. C. Essentials of WISC-V Assessment. Wiley, 2017.
Frequently asked questions
What is the most accurate IQ test for kids?
An individually administered test given by a psychologist, such as the WISC-V for ages 6 to 16 or the Stanford-Binet 5. No online test for children comes close, because none observes the child or uses comparable norms.
What is the average IQ of a child?
100, as for adults. Children's tests compare each child with others of the same age, so the average is 100 at every age.
What is a normal IQ for a 7 year old?
The same as at any age: 85 to 115 covers about two thirds of children, and 90 to 109 is the average band. Scores at 7 can still shift by several points as the child develops.
What is a good IQ score for kids?
Above 110 is above average, above 120 is high, and 130 or more is in the range many gifted programmes look for. A child's score matters less than the profile of strengths and difficulties behind it.
What IQ is considered gifted?
Commonly 130 or above, the top 2%, though programmes vary and many use 125 or combine IQ with other evidence such as achievement and teacher observations.
Is 130 IQ gifted?
Yes, 130 is the most common threshold for giftedness. Because of measurement error, a measured 128 and 132 are not really different, which is why good programmes look at more than one number.
Is 120 IQ gifted?
Usually not by IQ alone. 120 is high, above about 91% of children, but most programmes set the bar at 125 to 130. Some identify children at 120 when other evidence points to high ability.