When IQ testing is and isn't appropriate
IQ testing for children is a clinical and educational tool with specific appropriate uses — not a routine milestone. Major psychological and educational bodies including the American Psychological Association and the National Association of School Psychologists do not recommend routine IQ testing for all children. Assessment should be driven by a specific question that testing can answer.
Appropriate reasons to test: suspected learning disability or specific developmental delay requiring formal diagnosis; evaluation for a gifted or accelerated education programme; neuropsychological assessment following brain injury, serious illness, or significant academic regression; and educational planning when a child's needs are clearly not being met by standard provision and the cause is unclear.
When testing is generally not appropriate: parental curiosity without a specific concern; competitive comparisons between siblings or classmates; confirming a belief that a child is gifted without an educational programme attached to the outcome; and before age 5–6, when scores are too unstable to inform meaningful decisions.
Which IQ test is used at each age
There is no single IQ test for all children — the right instrument depends on the child's age, the reason for testing, and whether any factors (language difficulties, motor impairments, autism) might make certain tests less valid. The table below covers every major instrument currently in clinical use in English-speaking countries.
| Test | Age range | What it measures | Administered by | Approx. cost (US) | Best used for |
|---|---|---|---|---|---|
| WISC-V Wechsler Intelligence Scale for Children, 5th Ed. |
6–16 yrs | Full Scale IQ + 5 index scores: Verbal Comprehension, Visual Spatial, Fluid Reasoning, Working Memory, Processing Speed | Clinical / School psych | $1,500–$3,500 | Learning disability diagnosis, gifted evaluation, school-age cognitive profiling |
| WPPSI-IV Wechsler Preschool & Primary Scale of Intelligence |
2.5–7.7 yrs | Full Scale IQ + age-appropriate index scores; reduced verbal demand at lower end | Clinical psychologist | $1,500–$3,000 | Preschool developmental concerns, early gifted identification, school readiness |
| Stanford-Binet 5 (SB5) |
2–85 yrs | Full Scale IQ, Verbal and Nonverbal IQ, 5 factor scores; higher ceiling than WISC-V | Clinical psychologist | $1,500–$3,000 | Very young children, very high ability (gifted/profoundly gifted), autism assessment |
| Bayley-4 Bayley Scales of Infant & Toddler Development |
1–42 months | Cognitive, language, motor, social-emotional, and adaptive behaviour scales — not a traditional IQ test | Clinical / developmental paediatrician | $1,500–$2,500 | Developmental delay screening in infants and toddlers; early intervention planning |
| CAS2 Cognitive Assessment System, 2nd Ed. |
5–18 yrs | PASS model: Planning, Attention-Arousal, Simultaneous, Successive processing — minimal verbal load | Clinical psychologist | $1,500–$3,000 | Children with language difficulties, ELL students, dyslexia, where verbal tests may underestimate ability |
| Raven's Progressive Matrices | 5–65 yrs (various editions) | Fluid reasoning / abstract pattern recognition only — no verbal component | School / clinical | $300–$800 | Screening, research, non-verbal ability assessment; not a full IQ assessment alone |
| KABC-II Kaufman Assessment Battery for Children |
3–18 yrs | Sequential and simultaneous processing, learning, planning, knowledge — dual theoretical framework | Clinical psychologist | $1,500–$3,000 | Children with autism, hearing impairment, culturally diverse populations where other tests may be less appropriate |
What IQ scores mean at different ages
The key principle to understand is that IQ is always relative to age. A score of 100 means your child is performing exactly at the average for other children the same age. The test automatically adjusts for developmental stage — a 7-year-old and a 14-year-old can both score 100, but they are being compared to completely different groups of peers.
The table below shows what different score ranges mean in terms of population standing and practical implications for educational planning, across the age groups where testing is most commonly requested.
| Score range | Classification | % of children at this level | What it means practically | Typical educational implication |
|---|---|---|---|---|
| 130+ | Very Superior / Gifted | Top 2.3% | Child is performing significantly above age peers across most measured abilities. May be bored or under-challenged in standard curricula. | Gifted programme eligibility; curriculum enrichment; possible grade acceleration depending on social maturity |
| 120–129 | Superior | Top 6–9% | Clearly above average; likely to progress quickly through standard curriculum. May qualify for some gifted programmes (threshold varies by district). | Advanced coursework; enrichment activities; monitor for gifted programme eligibility if 125+ |
| 110–119 | High Average | Top 16–25% | Above average performance; should manage standard curriculum comfortably and likely exceed it in many areas. | Standard provision with extension opportunities; no special services typically required |
| 90–109 | Average | Middle 50% | Age-appropriate performance across measured abilities. A score in this range is entirely normal and not a cause for concern. | Standard curriculum; no special assessment or services required based on IQ alone |
| 80–89 | Low Average | Bottom 9–25% | Below average but within the normal range; may struggle with aspects of standard academic curriculum. | Additional instructional support; close monitoring; assessment for specific learning difficulties if struggling significantly |
| 70–79 | Borderline | Bottom 2–9% | Significantly below average; likely to need consistent educational support and accommodations. | Individualised Education Programme (IEP) consideration; learning support services; assessment for intellectual disability if other indicators present |
| Below 70 | Intellectually Disabled range | Bottom 2% | Requires comprehensive evaluation — a score alone is insufficient for diagnosis. Intellectual disability diagnosis also requires significant adaptive behaviour deficits. | Specialist educational placement; IEP; multi-disciplinary assessment essential |
One critical point: the index scores on the WISC-V are often more practically useful than the Full Scale IQ. A child with a large gap between Verbal Comprehension (e.g. 125) and Processing Speed (e.g. 85) may show an average FSIQ around 105 — a composite that masks a profile of real strengths and real difficulties. The pattern of scores matters as much as the number.
How much does testing cost — and how to get it
The cost of IQ testing varies substantially depending on who administers it and under what circumstances. There are three main routes:
| Route | Cost | Timeline | What you receive | Best for |
|---|---|---|---|---|
| School district referral (IDEA evaluation) | Free | 60-day legal deadline from written request to evaluation completion (varies by state) | Psychoeducational evaluation including IQ test, academic achievement tests, and eligibility determination for special education services | Suspected learning disability or developmental delay; concern about school performance; child may qualify for IEP |
| Private psychologist (standalone IQ) | $800–$1,800 | Appointment within days to weeks; report within 2–3 weeks of testing | IQ test (usually WISC-V), detailed written report with score interpretation and recommendations | Gifted programme admission; parental curiosity; second opinion; faster than school process |
| Private psychologist (full psychoeducational) | $1,500–$3,500 | 2–4 week process; report within 2–4 weeks of final session | Full cognitive battery (WISC-V or equivalent), academic achievement, attention, social-emotional assessment, diagnostic conclusions, and detailed recommendations | Suspected ADHD, dyslexia, autism, or multiple co-occurring concerns; diagnostic clarity needed; more comprehensive than school evaluation |
| University training clinic | $200–$600 | Longer wait (1–3 months typically); supervised graduate students | Full psychoeducational evaluation; supervised by licensed psychologist | Cost-sensitive families; not urgent; comfortable with supervised trainees |
| Insurance-covered evaluation | Copay or free | Variable; depends on referral process and available providers | Varies by plan; may cover neuropsychological evaluation when medically necessary (e.g. suspected ADHD, post-injury) | When evaluation is tied to a medical diagnosis; check specific plan benefits before proceeding |
Important: Under the Individuals with Disabilities Education Act (IDEA), US parents have the right to request a free school-based evaluation at any time in writing. The school must respond within a set period and either conduct the evaluation or provide written justification for refusal. This is a legal right, not a favour — schools cannot deny a reasonable evaluation request without documentation.
How to find a qualified psychologist
IQ testing for children should only be administered by a licensed psychologist — not a counsellor, social worker, or teacher, regardless of their general credentials. Specifically, you want someone with training in psychoeducational or neuropsychological assessment with children. Here is how to find one:
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APA Psychologist Locator The American Psychological Association's locator at locator.apa.org allows filtering by specialty including "child/adolescent" and "psychological testing". All listed psychologists are APA members; filter further for those listing "psychoeducational assessment" or "neuropsychological assessment" as a specialty.
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Your child's school district School districts maintain lists of approved private evaluators they accept for special education purposes. Even if you are seeking a private evaluation, asking the school for their approved list ensures the report will be accepted without challenge when you present results.
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Your state's licensing board Every state has a psychology licensing board with a public directory. Verify that your potential provider holds a current license in good standing. The credential you want to see: Licensed Psychologist (LP or PhD/PsyD in Psychology) — not Licensed Professional Counsellor (LPC) or Licensed Clinical Social Worker (LCSW), who are not trained in psychoeducational assessment.
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University psychology departments Many universities with doctoral psychology programmes run supervised training clinics that offer full evaluations at significantly reduced cost. The evaluators are doctoral students, but all work is supervised by licensed faculty. Search for "[your city] university psychology training clinic" or "child assessment clinic".
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Questions to ask before booking Ask: What tests do you use for a child this age? How long is the assessment and the report? What is included in the cost? Do you provide feedback sessions for parents? Will the report be accepted by our school district? A qualified evaluator will answer these clearly and without pressure.
How reliable are childhood IQ scores — really?
One of the most important things parents can understand about childhood IQ testing is that scores are not fixed pronouncements. They are measurements taken at a point in time, with measurement error, on an ability that is still developing.
The technical reliability of a well-administered WISC-V is high within a testing session — the test produces consistent scores when administered correctly. The question is whether that score is stable over time, which is a different and more practically important issue.
Research on the stability of childhood IQ gives a nuanced picture. Correlations between IQ scores taken years apart increase substantially with age: a score at age 4 correlates with age-18 IQ at approximately r = 0.4–0.5. By age 8, that correlation rises to roughly 0.6–0.7. By age 12–14, it is approximately 0.7–0.8. This means that even by early adolescence, a meaningful proportion of children's scores will shift over time.
Several factors are known to produce genuine changes in children's IQ scores over time: the quality of schooling (several points difference between high and low-quality schools has been documented), major health events, significant changes in the home environment, and the natural developmental trajectory of the child. This is one reason single scores in young children should never be treated as definitive.
Gifted identification: what the thresholds actually mean
Most gifted education programmes in the United States use an IQ cutoff of 130 as a primary eligibility criterion — corresponding to approximately the top 2.3% of the population. Some programmes use 125, and a small number of highly selective programmes (sometimes called "profoundly gifted" programmes) require 145 or above.
There are important caveats to these thresholds. First, scores at the extremes of ability distributions are less reliable — a score of 132 and a score of 128 may not be meaningfully different given measurement error, yet one qualifies and the other does not. Second, different IQ tests use slightly different scales and the same child may score differently on the WISC-V vs. the Stanford-Binet 5 at the extremes. Third, gifted programmes vary enormously in quality — the test score is the entry requirement, not a guarantee of what the programme delivers.
Parents seeking gifted identification should be aware that the optimal testing age for gifted identification is generally 7–10 years. Earlier than this, scores are too unstable to support programme placement decisions. It is also worth knowing that the Stanford-Binet 5 has a higher ceiling than the WISC-V and is often preferred for children suspected to be in the highly gifted range (IQ 145+) because the WISC-V can "floor out" at the top end.
What to actually do with the results
Receiving an IQ assessment report for your child can be overwhelming — they are often 20–30 pages long and full of psychometric terminology. Here is a practical framework for what to do next.
Read the recommendations section first. This is the part that matters most for action. Psychologists are trained to translate scores into concrete educational recommendations. If the recommendations are vague or absent, ask for a feedback session to discuss them specifically.
Focus on the profile, not the number. A child with a FSIQ of 112 but a Processing Speed Index of 78 has a very different profile from a child with a FSIQ of 108 and scores between 100–115 on all index scales. The first child may have real difficulties with timed tasks and written work that the composite score hides. Bring this question explicitly to the feedback session: "Are there any significant discrepancies between index scores, and what do they mean for my child's education?"
Do not share the score number casually. Children who hear their IQ score — or who hear it discussed by adults — can develop fixed self-concepts around it that are counterproductive. If a child hears "you have an IQ of 95" they may conclude they are not smart; if they hear "you have an IQ of 135" they may conclude effort is unnecessary. Neither framing is helpful. Focus conversations on strengths and strategies, not numbers.
Present the report to the school. A private evaluation report carries formal weight in most educational systems. Schools are required to consider the findings when making placement and support decisions, even if they were not the ones who commissioned the evaluation. Request a meeting with your child's teacher and any relevant specialists to discuss the findings and what adjustments are appropriate.
For more on what IQ scores predict and what they do not, see our article What Is IQ? For information on the specific threshold for gifted programmes, see What IQ Score Is Considered Gifted? And for a look at how IQ changes across the full lifespan, see Average IQ by Age.
Frequently asked questions
What is a good IQ score for a 10-year-old?
A score of 100 is average for any age group — IQ tests are normed specifically to the child's age, so 100 always means "exactly average for your age." Scores between 90–110 are in the average range and are entirely normal. Scores of 110–120 are high average, 120–130 are superior, and above 130 is the very superior or gifted range. The same scale applies at every age — a 10-year-old and a 14-year-old scoring 105 are both performing slightly above average for their respective age groups.
At what age can you test a child's IQ?
Formal cognitive assessment can begin as early as age 1–2 with instruments like the Bayley Scales, though these are developmental measures rather than traditional IQ tests. The WPPSI-IV covers ages 2.5–7.7 years. The WISC-V, the most widely used children's IQ test, starts at age 6. Most psychologists recommend waiting until at least 6–7 for results that will meaningfully inform educational decisions, as scores before age 5 have limited predictive validity for later IQ and can change substantially.
How much does an IQ test for a child cost?
A private full psychoeducational evaluation including IQ testing typically costs $1,500–$3,500 in the US. A standalone IQ-only assessment with a private psychologist runs approximately $800–$1,800. School districts are legally required to provide free evaluation under IDEA when there is a suspected learning disability — parents can formally request this in writing. University training clinics offer supervised evaluations for $200–$600. Private insurance rarely covers standalone IQ testing but may cover evaluation when it is part of a diagnostic workup for ADHD or a learning disability.
What is the WISC-V and what does it measure?
The WISC-V (Wechsler Intelligence Scale for Children, Fifth Edition) is the most widely used individually-administered IQ test for children aged 6–16. It takes approximately 60–90 minutes and is always administered by a licensed psychologist. It produces a Full Scale IQ (FSIQ) and five index scores: Verbal Comprehension (language-based reasoning), Visual Spatial (2D/3D pattern understanding), Fluid Reasoning (novel problem-solving), Working Memory (holding and manipulating information), and Processing Speed (quick, accurate visual scanning). The index scores are often more useful than the composite FSIQ for educational planning.
Should I have my child IQ tested?
Testing is appropriate when there is a specific question that testing can help answer: a suspected learning disability, evaluation for a gifted programme, assessment after illness or injury, or understanding why a child is struggling when the cause is unclear. Routine testing out of curiosity is not recommended — especially before age 8, when scores are less stable and the risk of premature labelling is real. If your child's school or paediatrician has raised concerns, or if your child is being considered for a gifted programme, testing is likely appropriate. Contact your child's school psychologist or a private educational psychologist for guidance specific to your situation.
How reliable are IQ test results for children?
A well-administered clinical IQ test like the WISC-V is technically reliable within a testing session — it produces consistent results. But stability over time increases significantly with age. Below age 5, scores have low predictive validity for adult IQ. From age 6–8, the correlation to age-18 IQ is approximately 0.5–0.6, meaning meaningful changes are common. By ages 12–14 the correlation is 0.7–0.8 — much more stable. A single childhood score, especially in young children, should inform educational planning but never be treated as a permanent or definitive measure of a child's potential.