What are age scores?

Age scores, also called age-equivalent scores, are supposed to help people understand how a person’s test score compares to other people of the same age. They are often provided to teachers and parents to show how children scored on achievement tests compared to their age peers. A common age-equivalent abbreviation is AE

Age scores are reported with a hyphen. The first number refers to age in years and the second number refers to the age in months. A score of 8-4 is supposed to mean a test performance typical of children age 8-years and 4-months.

The scores appear convenient and make a kind of common sense. An age score of 7-6 is supposed to mean that a child earned a test score similar to children age 7-years and 6-months. But there are problems with the scores.

What tests report age scores?

Age scores are commonly reported with results of achievement tests. They are sometimes reported with results of intelligence tests. Old intelligence tests reported a mental-age score (MA).

What’s the problem with age-equivalent scores?

The scores create an inaccurate impression of performance for children who are much younger or older than the age comparison group. An age score of 7-6 obtained by a 5-year-old does not account for all of the knowledge or ability that is typical of a child age 7-6. Similarly, a teen aged 13 may have different skills than represented by an age score of 7-6, which of course suggests a very low skill level for a 13-year-old.

The reliability of age scores for children whose actual age is much lower or higher than the reported age score varies from the reliability values for children close to the age-score. The reliability of scores is not a stable characteristic. Retesting can yield very different results on retesting when a very high or low score is obtained.

Age scores do not allow for an accurate comparison over time because the content of the tests and the abilities of children change dramatically as children age. Reading tests and reading abilities are very different for children age 7 and those age 14. Children learn very different math concepts at age 12 than do those at age 8. To say an 8-year old has an age score of 12-1 in math is hardly accurate.


Read more about age-equivalent and other scores in


Age score differences do not provide parents and teachers with an accurate picture of delays and advancement. A child who is one year behind peers in math at age 8 is further behind than is a child who is one year behind at age 15. The gains children make in reading, math, and other skills are greater in the early years of life than in later years.

Age units are inaccurate compared to other scores. Age scores report differences in months but child development is uneven—especially when it comes to mental abilities like reading comprehension, spelling, and visual memory. Comparisons do not make a lot of sense for children of the same chronological age who earn different age scores. Two children having the same chronological age of 8-years and 2-months but different reading comprehension test age scores of 6-10 and 9-3 have different skill levels. But concluding they are 2-years and 5-months apart on reading comprehension is not reasonable because only a small sample of skills are assessed on tests. Even worse might be the perception that the score difference is somehow fixed. Differences this large will almost always change over time.

There are problems with the samples of children at different ages when the age scores are very different from the chronological age. Consider children with an actual age of 8-3. If one obtains a test age score of 5-6 and another of 11-3. A lot of 8-year-olds can take a test designed for 8-year-olds but how many 5-year-olds or 11-year-olds take the same test? The problem is having an accurate sample group for comparison purposes.

What scores are better than age-equivalent scores?

Several scores are better than age-equivalent scores. Most tests report standard scores (SS) and national percentile rank (NPR) scores on children’s achievement tests. These scores compare children to others of the same age group.

What about grade scores?

Grade scores have the same problems as do age scores. A grade score is reported as a grade number with a decimal and a second number referring to the month of a school year. A grade score of 5.6 means the sixth month of grade 5. 

You can see my glossary of test and statistical terms at this website:

Sutton, G. W. (2017). Applied statistics: Concepts for counselors. Springfield, MO: Sunflower. Amazon  Paperback ISBN-10: 1521783926, ISBN-13: 978-1521783924

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