The Nelson-Denny Reading Test measures vocabulary, reading comprehension, and reading rate in about 35 minutes. See who takes it and what scores mean. (150 chars)
Dr. Russell T. WarneChief Scientist
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The Nelson-Denny Reading Test is a timed reading assessment with two scored sections, vocabulary and reading comprehension, plus an optional reading rate measure taken during the first minute of the comprehension section. The current revision, Forms I and J, was published in 2018 and is sold by the assessment company Riverside Insights for students from high school through college. Standard administration takes about 35 minutes. Colleges use it to place students in reading courses and track progress, several police academies use it to screen applicants, and clinicians frequently administer it when documenting learning disabilities or ADHD in adults. This article covers what each section measures, who takes the test, how its extended-time administration works, and why a reading screen is a different instrument from an intelligence test.
A brief history and the current forms
The test has been part of American education for nearly a century. It was created in 1930 by Martin J. Nelson and Emerson Charles Denny, who taught at Iowa State Teacher's College, as a way to measure the reading ability of high school and college students. Successive revisions have kept the same basic recipe: a vocabulary section, a comprehension section built on textbook-style passages, and parallel forms so that a student can be tested twice without seeing the same items.
The current edition, Forms I and J, was prepared by Vivian Vick Fishco and published in 2018. According to Western Psychological Services, one of the companies that distributes the test, the norms are based on a sample of students ages 14 years, 0 months through 24 years, 11 months who were enrolled in high school, two-year, or four-year college programs. The "norm sample" is the comparison group that gives raw scores their meaning, so this range matters: the Nelson-Denny compares an examinee with students, and it was never normed on the full adult population.
Scores are reported as grade and age equivalents, percentile ranks, and "index scores," which are standard scores set to a mean of 100 with a standard deviation of 15, the same metric used for IQ scores. The two forms are equated, meaning they can be used interchangeably as a pretest and a posttest. Riverside Insights, the test's publisher, markets it for pre- and post-testing and for tracking growth in general reading proficiency.
What the two sections measure
The Nelson-Denny is deliberately simple in structure. Under standard timing, the whole test fits inside a class period.
• Vocabulary (15 minutes, 80 items): each item presents a short stem and five answer choices, and the examinee picks the word or phrase that best fits the meaning. The Charlotte-Mecklenburg Police Department's applicant study guide describes the words as similar to those on an eleventh-grade English test.
• Reading comprehension (20 minutes, seven passages): the passages are drawn from humanities, science, and social science textbooks, followed by about 36 multiple-choice questions in total. Roughly half the questions are literal, asking what the passage stated, and half are inferential, asking what the passage implies.
• Reading rate (the first minute): exactly one minute into the comprehension section, examinees mark the last sentence they were reading in the first passage. This yields a words-per-minute estimate. It is a measure of speed only, and says nothing by itself about how much the reader understood.
The publisher also offers an extended-time administration, which stretches the total testing time to as much as 56 minutes. That option exists because the standard version is heavily speeded, a point that becomes important in disability evaluations, discussed below.
Who takes the Nelson-Denny?
The test shows up in three main settings, and in all of them it works as a screening instrument rather than a diagnostic one.
• College reading placement and progress testing: colleges use the Nelson-Denny to decide whether entering students need developmental reading coursework and to measure whether reading programs are working. In that role it sits alongside broader placement instruments such as the ACCUPLACER, which covers math and writing as well as reading.
• Law enforcement academy screening: several police training programs require a minimum Nelson-Denny score before admission. The Reading Police Academy in Pennsylvania, for example, states in its application materials that officers must successfully complete the Nelson-Denny at the ninth-grade reading level, and that pre-service applicants must pass the Nelson-Denny along with psychological testing and an intelligence test. The Charlotte-Mecklenburg Police Department likewise bases a "reading placement" on Nelson-Denny scores during applicant testing. Reading ability screens exist alongside the broader police written exam because academy coursework is reading-heavy, and agencies want evidence that recruits can handle it.
• Adult disability evaluations: psychologists evaluating adults for learning disabilities or ADHD often include the Nelson-Denny because it is one of the few reading measures with both standard-time and extended-time administrations, which lets an evaluator show how a client performs with and without time pressure.
Extended time and disability documentation
When a college student requests extra time on exams, the documentation usually has to show impairment in some academic skill. According to a 2019 analysis by Allyson Harrison and Kathleen Harrison in the journal Psychological Injury and Law, the Nelson-Denny is one of the most widely used tests for documenting impaired reading speed, and clinicians often employ it specifically to demonstrate the need for extra-time accommodations.
The same analysis explains why scores from it should be interpreted carefully. The test offers grade-based norms, so a graduate student can end up compared with a small, educationally elite group rather than with same-aged adults in general. Using the test's own normative data, the authors showed that the identical raw score can look average against a broad sample yet appear impaired against upper-grade norms. They concluded that grade-based norms should not be used for disability determination, and they note that earlier test reviewers judged the Nelson-Denny appropriate only as a rough screening measure, without validity for diagnosing reading disorders. The test manual itself warns that scores are not to be used for diagnosis.
None of this makes the test useless. A timed reading screen administered under standard and extended time can be genuinely informative inside a full evaluation. The point is that a low Nelson-Denny score alone does not establish a reading disability, and an evaluator who treats it that way is overreaching what the instrument can support.
How reading ability relates to general intelligence
Reading ability and intelligence overlap, and the vocabulary section is where the overlap is strongest. Vocabulary knowledge is one of the best single indicators of "crystallized intelligence," the store of knowledge and verbal skill a person accumulates over a lifetime, which is why vocabulary tests appear on nearly every major IQ battery.
The overlap is real but far from total. A meta-analysis by Peng Peng and colleagues in Psychological Bulletin, covering 680 studies and more than 370,000 participants, found that "fluid intelligence," the ability to reason through novel problems, correlates about .38 with reading performance. A correlation of that size means strong readers tend to reason well, and it also means most of the variation in each skill is independent of the other. Reading is a trained skill: it responds to instruction, print exposure, and language background in ways that reasoning ability does not. An adult who learned English as a second language, or who simply reads little, can post a mediocre Nelson-Denny score while reasoning at a high level. The reverse also happens, since a fast, fluent reader is not necessarily a strong abstract reasoner.
The practical conclusion is that a reading test and an intelligence test answer different questions. The Nelson-Denny asks how well you read under time pressure compared with students. An intelligence test asks how well you reason across several distinct abilities compared with the general population.
Where the RIOT IQ test fits
If what you actually want is a profile of your thinking abilities rather than a reading screen, a reading test cannot supply it, because it samples one academic skill through a single verbal channel. The RIOT IQ test, the Reasoning and Intelligence Online Test, was developed by RIOT IQ with psychometrician Dr. Russell T. Warne for adults 18 and older. It includes 15 subtests across six cognitive indices: verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time. The test takes about 52 minutes and reports scores on the familiar mean-100, standard-deviation-15 scale, with a profile showing relative strengths across the six indices. Like the Nelson-Denny, it does not replace an individually administered diagnostic evaluation, and no honest test publisher claims otherwise. For an adult who wants to know how their reasoning compares with the adult population, rather than how fast they read textbook passages, you can take the RIOT IQ test at riotiq.com.
FAQ
How long is the Nelson-Denny Reading Test?
About 35 minutes under standard timing: 15 minutes for the 80-item vocabulary section and 20 minutes for the seven-passage comprehension section. The extended-time administration runs up to 56 minutes.
Is the Nelson-Denny an IQ test?
No. It measures vocabulary, reading comprehension, and reading rate. It does not assess fluid reasoning, spatial ability, working memory, or processing speed, so it cannot produce an IQ score, even though its index scores use the same mean-100 scale.
What score do police applicants need?
Requirements vary by agency. In Pennsylvania, the Reading Police Academy requires performance at the ninth-grade reading level, a standard tied to the state's municipal police training requirements. Check the specific agency or academy you are applying to.
Can you take the Nelson-Denny with extended time?
Yes. The publisher offers an optional extended-time administration, and evaluators often give both versions to show how a person's reading changes when time pressure is removed.
Can the Nelson-Denny diagnose dyslexia or ADHD?
No. Reviewers and the test manual agree it is a screening measure. Diagnosing a reading disorder or ADHD requires a comprehensive evaluation with multiple instruments and a clinical history.
Who publishes the Nelson-Denny Reading Test?
Riverside Insights publishes the current Forms I and J, released in 2018, and the test is also distributed through other assessment companies such as Western Psychological Services.
4. Reading Police Academy. (2026). Application information: Basic municipal police training course. readingpa.gov
5. Charlotte-Mecklenburg Police Department. (2023). Nelson-Denny Reading Test practice questions. charlottepolicejobs.org
6. Harrison, A. G., & Harrison, K. A. (2019). A critical analysis of the Nelson Denny Reading Test as a method of identifying reading impairment in adults. Psychological Injury and Law, 12, 17-28. queensu.ca
7. Peng, P., Wang, T., Wang, C., & Lin, X. (2019). A meta-analysis on the relation between fluid intelligence and reading/mathematics: Effects of tasks, age, and social economics status. Psychological Bulletin, 145(2), 189-236. doi.org
Hero photo: Reading glasses resting on an open dictionary page. Photo by Shixart1985, CC BY 2.0, via Wikimedia Commons.
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