For parents and teachers

Reading age test: measure the text, not the child

A reading age is a score on a standardized assessment given in a school, converted through a table normed on a national cohort in a particular year — it is not a property a web page can estimate, and any site returning one from a few questions has relabeled something else. What this page does instead is the decision you are actually making: paste the worksheet, the letter or the chapter, and four published readability formulas run over it in your browser, free and with no account, showing the words, sentences and syllables each number came from.

100% free
No signup
4 published formulas
Any pasted passage
Counts shown, not just scores

Paste the text you are judging

A worksheet, a letter going home, a page of the book you are deciding about. It is read in this tab and goes nowhere.

Press Ctrl+V anywhere on the page to drop in a passage from a book, a worksheet or a letter — no need to click the field first.

Try the three samples before your own text

They are there to show you what these formulas can and cannot see, using their own output rather than an argument. Two of the three are rated at roughly the same difficulty and are nothing like each other to read; the third is rated as graduate prose and is a set of directions to a corner shop.

A page from a children's story: Short sentences, ordinary words, and nothing assumed. Easy by the formulas and easy in fact — the case where they agree.
Short sentences about quarks: Same sentence length as the story, almost the same word length, and impenetrable unless you already know the subject. This is the demonstration: neither formula can see meaning.
One long sentence of directions: Plain words a child would know, in a single sixty-word sentence. The formulas rate it as graduate-level text; almost anyone can follow it.

How to judge whether a text suits a reader

Paste the real thing, read four numbers against each other, and treat the answer as a band.

Paste a real extract, not a sample sentence
Take a few hundred words of the actual document — the middle of the chapter rather than its opening line, the body of the letter rather than the heading. Every one of these formulas divides by the number of sentences, so a heading pasted on its own with no full stop is counted as one enormous sentence and comes back rated as graduate prose. If you have only a hundred words, the page says so and tells you which figure is least stable at that length.
Read the four figures against each other, not one of them alone
Flesch Reading Ease runs 0 to 100 with high meaning easy; Flesch-Kincaid and SMOG return US school grades; Gunning Fog returns years of formal education. They disagree because they weight sentence length against word length differently, and the spread between them is information: a tight cluster means the text is uniform, while a wide one usually means a few very long sentences or a few very heavy words are carrying the whole score. The panel lists both, so you can see which.
Convert to an age only at the end, and only for the text
Add five to a US grade to speak of it in years, because a US first-grade class is six to seven years old; English and Welsh year groups run one number higher than US grades, so a grade 4 text is roughly Year 5 material. That arithmetic describes how school systems are numbered. It says the text is pitched at readers of about that age, which is a different sentence from one about any particular reader, and it is the only one of the two this page can support.

Technical specifications

Formulas computed	Four, all from published definitions and all cited on screen: Flesch Reading Ease and Flesch-Kincaid Grade Level, plus Gunning (1952), The Technique of Clear Writing, McGraw-Hill and McLaughlin (1969), SMOG grading: a new readability formula, Journal of Reading
What each returns	Reading Ease is a 0-100 score where higher is easier; Flesch-Kincaid and SMOG are US school grades; Gunning Fog is years of formal education. SMOG usually lands a grade or two above the others because it was calibrated against full understanding of the passage rather than partial
Sample size handling	SMOG was defined on 30 sentences and is scaled to shorter samples with a warning saying so. Under 100 words the page flags every figure as unstable, and a passage with no terminal punctuation is flagged separately because it is being counted as a single sentence
How the counts are made	Sentences split on a full stop, question mark or exclamation mark followed by a space. Syllables by vowel groups with a silent terminal e removed. Gunning's complex-word rule is approximated: three or more syllables after stripping -es, -ed and -ing, excluding hyphenated words and capitalized words that are not sentence-initial
Grade to age	Grade plus five, giving a two-year band. A US first-grade class is six to seven years old, so grade 4 reads as roughly ages 9-10 and as English Year 5. This is arithmetic about school systems and is applied to the text, never to a reader
What the page will not output	A reading age for a person, a percentile, a standardized score or anything resembling a screening result. Those come from an assessment administered by somebody watching the reader, and no arrangement of these four numbers substitutes for one
Text handled	Any length, recomputed as you type or paste, English only — the constants in all four formulas were fitted to English sentence and syllable statistics and mean nothing applied to another language
What leaves the page	Nothing. The passage you paste is read by JavaScript in this tab, never sent anywhere and never stored, which is the reason the page can be used on a document you would not email to a stranger

Frequently asked questions

What is a reading age, exactly?

It is an age-equivalent score from a standardized reading assessment: a child sits a specific test, the raw score is converted to a standardized score against a sample of children of the same age, and a published table then reports the age at which that performance is typical. Every part of that depends on the particular test and the cohort it was normed on, in the year it was normed. Two tests can hand the same child two different reading ages without either being wrong, because they are two different scales, and neither of them is a general property of the child that a third party could compute independently.

Can a website work out my child's reading age?

No, and the ones that claim to are usually reporting something else under that name. Producing a reading age requires a standardization sample — thousands of children of known ages, sitting the same items under the same conditions — and no web page has one. What a browser can measure honestly is the difficulty of a piece of text, which is a genuinely useful number for choosing a book and a completely different quantity from a score about a reader. If a formal figure is what you need, the school can arrange the assessment that produces one.

The school said “reading age 8 years 4 months”. How precise is that?

Far less precise than the months suggest. An age-equivalent score is read off a table, and around the middle of the distribution a difference of one or two raw marks can move the reported age by several months, which means the last figure is mostly measurement noise. Age equivalents are also not an equal-interval scale: the gap between a reading age of 7 and 8 represents much more change in reading than the gap between 14 and 15, because reading develops fastest early. Most test manuals recommend the standardized score and its confidence band over the age equivalent for exactly this reason — ask for that instead, and ask for the band around it.

Which of the four formulas should I trust for a school text?

Use SMOG when the reader has to understand all of it and Flesch-Kincaid when they only have to get the gist. That is the actual difference between them rather than a preference: SMOG was calibrated against complete comprehension of the passage, while the Flesch family was fitted against partial comprehension scores, which is why SMOG typically returns a grade or two higher on the same text. Health and safety material is conventionally checked with SMOG for that reason. For a story a child will read for pleasure, the lower figures are the more realistic guide.

The formula says grade 3, but the passage is about cell division. Is it broken?

It is working exactly as designed, which is the problem. All four formulas take two inputs — how long the sentences are and how long the words are — and neither of those has any relationship to whether a reader has met the subject. A paragraph of short sentences built from short technical words scores as easy prose and is unreadable to anyone outside the field, and the sample marked as short sentences about quarks in the tool above demonstrates it with its own output. Use the numbers to catch text that is needlessly heavy, never to certify that text is understandable.

Does any of this work for text in another language?

No. Every constant in these four formulas was fitted to English, on English school and training material, and the relationship between syllable count and difficulty is a property of the language rather than a universal. Applying them to German, where compounds pile syllables into single common words, or to Chinese, where syllables are not what varies, produces a number with no meaning at all. Several languages have their own adaptations with their own constants; those are the ones to look for, and none of them is what runs on this page.

Why does the SMOG number come out highest almost every time?

Because it is measuring a stricter target and because it counts differently. McLaughlin (1969), SMOG grading: a new readability formula, Journal of Reading set the formula against readers who understood the passage completely, where the Flesch family was fitted to partial comprehension, so the same text needs a more advanced reader to clear the higher bar. It also works from the count of words with three or more syllables and from nothing else about word length, so a text with a handful of very long words in otherwise plain sentences pushes SMOG up while barely moving Reading Ease. When the two diverge sharply, look at the list of long words in the panel — that is usually where the divergence is coming from.

Where a reading age comes from, and what to use instead

The route from a child sitting a test to the phrase “reading age 9.2” has three steps, and each one loses something. The child answers a fixed set of items and gets a raw score; the raw score is compared with children of the same age in the test publisher’s standardization sample, producing a standardized score with a confidence band around it; and then a lookup table converts that back into the age at which the raw score is typical. The last step is the one to be careful with. An age equivalent looks like a measurement in years but behaves nothing like one: reading develops fast at six and slowly at fifteen, so a fixed number of extra marks buys a child several months of reading age in the middle of primary school and a couple of years of it in secondary. That is why test manuals generally put the standardized score and its band first and the age equivalent in a smaller column — and why a reading age quoted to the month, from a test whose norms may be a decade old, is a number with far less inside it than it appears to have. It also cannot be reconstructed from anything a browser can observe, which is the honest reason this page does not offer one.

The decision most people are actually making when they search for this is narrower and answerable: is this particular text right for this particular reader. Readability formulas were built for exactly that screening job — Gunning wrote his for newspaper copy desks and McLaughlin wrote SMOG for material that had to be understood completely rather than approximately, which is why the two disagree by a grade or two on the same paragraph and why health services check leaflets with the stricter one. Running four of them at once is not indecision; the spread between them is the useful output. When all four cluster, the text is uniform and the number means something. When they scatter, the score is usually being driven by two or three enormous sentences or a handful of very long words, and the panel lists both so you can go and look. What none of them can do is see whether the reader has met the subject before, and no amount of averaging fixes that.

If you want something measured about the reader rather than the page, measure it directly rather than inferring it from a formula. The reading level test climbs a ladder of graded passages and reports the hardest one handled, which is the closest thing on this site to what a placement test does, and the comprehension test separates errors of detail from errors of inference, which is the distinction that tells a teacher what to work on. Where reading itself is the obstacle, the non-verbal reasoning test asks a reasoning question with no text in it at all, which is the reason that format exists in school assessment; and the spelling test looks at the writing side of the same skill. None of those returns an age either, for the same reason this one does not.

This is a measurement exercise, not a clinical assessment. It reports what you did on this page against a stated reference and nothing more — it cannot establish a reading difficulty, a language delay or a specific learning difficulty in a child or an adult. Only a qualified professional, working with more than a browser, can make that judgment.

Where the passage you paste is read

Every number on this page is worked out by JavaScript running in the tab you are reading it in. Your answers, your reaction times and your score are never uploaded, logged or kept — which is also why the test carries on working after you disconnect from the network, and why nothing here can be held back behind an email address.

The text you paste is held in a JavaScript variable while the four formulas run over it and is discarded when you clear the box or close the tab — it is never sent anywhere, which is what makes the page usable on a pupil’s work, a medical letter or a draft nobody else has seen yet.

The four figures and the counts behind them go onto your own clipboard whenever you ask for them, which is the only copy that exists once the tab closes: there is no saved history to come back to, nothing to delete afterwards, and no address to leave before the numbers appear.