Average IQ Compared: Australia vs the US and What PISA Can Tell Us

What did PISA 2022 show?

The OECD reported these mean scores for 15-year-old students:

The pattern is not a one-direction “intelligence” ranking. Australia scored above the OECD average in all three subjects. The United States was close to the OECD average in mathematics and above it in reading and science. On the PISA scale, the US was higher in reading while Australia was higher in mathematics and science.

Proficiency shares add context. In Australia, 74% of students reached at least Level 2 in mathematics, 79% did so in reading, and 80% in science. In the United States, the corresponding shares were 66%, 80%, and 78%. Level 2 means students can perform defined tasks—for example, interpreting a simple mathematical situation or identifying a main idea in a moderately long text. It is not an IQ threshold or percentile.

The top end also differs by subject. Australia reported 12% of students at mathematics Levels 5–6 and 13% at science Levels 5–6. The United States reported 7% and 11%, respectively. Australia’s reading top-performer share was 12%; the US reported 14%. A profile across domains is more informative than a single combined label.

Why are PISA scores not IQ scores?

PISA asks students to apply learned knowledge and reasoning in school-related, real-world-like tasks. An IQ battery samples selected cognitive abilities—often verbal comprehension, fluid reasoning, working memory, visual-spatial reasoning, and processing speed—under standardized individual administration. Both may involve reasoning, but they measure different constructs and have different norm groups.

PISA scores are reported on a subject-specific scale around an international reference distribution. IQ scores are usually reported on a 100/15 deviation scale. There is no legitimate arithmetic operation that turns 487 PISA mathematics into an IQ of 103, or 465 into an IQ of 98. A conversion would require a representative linking study in which the same students completed both assessments, with published reliability and measurement-error analysis. The OECD country notes do not provide such a crosswalk.

What sampling cautions matter for Australia and the US?

PISA 2022 was a special edition after the COVID-19 delay. The OECD flagged caution for both Australia and the United States because one or more sampling standards were not reached. In Australia, student response rates fell below the minimum target, and the OECD said a small residual upward bias could not be completely excluded. The US note also asks readers to interpret estimates with the technical guidance and confidence intervals.

These cautions do not make the assessment useless. They mean a difference should be treated as an estimate with uncertainty, not as an exact ordering of every student or a biological national trait. The sample also excludes adults, children outside the target age, and people not represented in the school frame. PISA describes education-system outcomes for a defined cohort.

What might explain the Australia–US pattern?

Education systems differ in curriculum, school funding, teacher preparation, assessment, student demographics, language, health, and access to learning resources. Within both countries, socioeconomic status predicts performance. In Australia, the OECD reported a 101-point mathematics gap between the most advantaged and disadvantaged quarters, similar to the OECD average gap. The US has its own substantial differences by state, district, and household resources.

Those factors are not excuses; they are part of what the results measure. A student’s opportunity to learn, familiarity with the test format, and school context can affect PISA performance. None of those observations lets us infer that Australians or Americans have a fixed inherited level of intelligence.

The long-term trend matters too. Australia’s 2022 results were broadly stable compared with 2018 but had declined over the longer period in all three subjects. The US mathematics result fell compared with 2018, while reading and science were about the same. Changes in schooling and social conditions can move achievement results without changing an imagined national IQ.

Why do online Australia–US IQ rankings disagree?

Online lists often mix old studies of children, self-selected adult quizzes, school scores, and model-based estimates. One source may anchor 100 to a worldwide reference sample; another may use a national norm. Translation, test familiarity, internet access, and socioeconomic selection can all shift the observed average. A two- or three-point gap is often smaller than the uncertainty introduced by these choices.

Before trusting a comparison, check:

1. Which named test and norm edition produced each score?
2. Are the age ranges, language versions, and administration conditions equivalent?
3. Was the sample probability-based, and were response rates and weights reported?
4. Is the outcome IQ, PISA achievement, or another skill measure?
5. Are confidence intervals and limitations shown?

If the answer is missing, the decimal is a rough online estimate—not evidence that one nationality is smarter.

How should an individual compare IQ across Australia and the US?

Use a validated, age-appropriate assessment with norms suitable for the person’s language and background. The report should name the instrument and edition, give a percentile and confidence interval, and explain index scores. A professional can also consider sleep, health, education, sensory factors, and test familiarity.

An online quiz can be informal practice, but it should not be used for diagnosis, school placement, employment, or cross-national judgments. PISA or another school survey cannot replace an individual cognitive assessment.

Related

Average IQ in Australia: How the Country Compares

The average IQ in Australia is estimated at roughly 98 to 100 on a scale where the global mean is set to 100, placing it near the top tier. Here is where that number comes from and why it is soft.

Related

Average IQ in the United States: How the US Compares

The average IQ in the United States is commonly estimated near 98, where the global mean is set to 100. Here is where the number comes from and why it is shaky.

Q: Which has the higher average IQ, Australia or the US?

A: There is no authoritative national IQ comparison. PISA 2022 found Australia higher in mathematics and science, while the US was higher in reading, but those are student achievement scores—not IQ points.

Q: What were the PISA 2022 scores for Australia and the US?

A: Australia scored 487 in mathematics, 498 in reading, and 507 in science. The US scored 465, 504, and 499. These scores describe sampled 15-year-old students on PISA’s subject scales.

Q: Does a higher PISA score mean a higher national IQ?

A: No. PISA measures applied knowledge and skills, while IQ batteries use different constructs, norm groups, and scoring. There is no direct PISA-to-IQ conversion.

Q: Are the Australia and US PISA results perfectly precise?

A: No. The OECD flagged sampling cautions for both countries in 2022, including Australia’s lower response rate. Interpret country means with their confidence intervals and technical notes.

Q: How can I compare my own IQ with someone in another country?

A: Use comparable, professionally normed assessments and interpret the percentile with its confidence interval. Do not compare online raw scores or PISA results as if they were individual IQ scores.

References

• OECD. PISA 2022 Results: Australia country note.
• OECD. PISA 2022 Results: United States country note.
• OECD. PISA 2022 Results: How did countries perform?.
• American Psychological Association. Deviation IQ.

Last updated: July 19, 2026