Reading Level Calculator
Calculate the reading level and readability score of any text using the Flesch-Kincaid formula. Find out what grade level your content targets.
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How to use this calculator
The Flesch-Kincaid Grade Level estimates the US school grade needed to comprehend the text. Lower scores = easier to read. Flesch Reading Ease (0–100) inverts this: higher = easier.
- 1
Paste your article, blog post, or page content into the text area; at least 10 words are needed.
- 2
Read the Flesch Reading Ease score (0–100, higher = easier) and the FK Grade Level.
- 3
Check the Words, Sentences and Syllables rows; a sentence count that looks wrong means the score is unreliable.
- 4
Compare the result with the audience you are writing for; the label bands shown are the tool’s own.
Frequently asked questions
Which formulas does the calculator use?
Flesch Reading Ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words). Flesch-Kincaid Grade = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. Ease is displayed clamped to 0 to 100 and the grade is floored at 0; the ease label is chosen from the unclamped value.
How does it count sentences and words?
Sentences are the non-empty pieces left after splitting the text on runs of . ! and ?. Words are whitespace-separated tokens that contain at least one letter or digit, so a lone dash or bullet is ignored. Fewer than 10 words returns an error instead of a score.
How are syllables counted?
For each word the tool lowercases it, strips everything except a to z, and counts groups of consecutive vowels (a, e, i, o, y, u) as syllables. A final silent e removes one syllable when the word has more than one group, except after consonant + le, so “table” and “simple” keep two syllables. Digits-only tokens contribute zero. It is a heuristic and will be wrong for some words.
Why does the ease label disagree with the grade level?
They come from different scales. The ease label is a lookup on the 0 to 100 score, while the grade is computed by its own formula. The tool’s default sample shows it: ease 34.8, labelled Difficult (college level), but grade 10.4. Do not expect the two descriptions to match.
What does the “SEO guidance” line mean?
It is a fixed message chosen from the grade: up to 8 gives “Good for general web audience”, up to 12 gives “Suitable for informed readers”, above 12 gives “Consider simplifying for broader reach”. Those cut-offs are the tool’s own. The tool does not claim that readability affects rankings.
How are headings, bullet lists and abbreviations treated?
Poorly, by design of the method. Lines without ending punctuation are merged into one long sentence, which raises the grade, while abbreviations and decimals such as “e.g.” or “3.5” create extra sentence breaks, which lowers it. Add full stops to list items or score prose paragraphs separately.
Does it work for languages other than English?
The formulas and the vowel-group syllable rule are built around English. Results for other languages are not meaningful.
Flesch Reading Ease and Flesch-Kincaid grade as this calculator computes them
The counts that feed the formulas
Two published formulas are used, Flesch Reading Ease and Flesch-Kincaid Grade Level, and no others. Both need three counts. Sentences come from splitting on runs of . ! and ?, words are whitespace tokens that contain a letter or digit, and syllables are estimated from vowel groups. The tool turns these into average words per sentence and average syllables per word, then applies the formulas. At least 10 words are required. Because short sentences and short words both push the scores toward easy, rewriting a long sentence moves the result faster than swapping single words.
Bands built into the tool
The ease label comes from the unclamped score, so a result displayed as 0.0 or 100.0 may have been far outside that range. The SEO guidance line reads the grade instead: up to 8 gives one message, up to 12 another, and above 12 a third. These cut-offs are the tool’s own.
| Ease score | Label |
|---|---|
| 90 or more | Very easy (5th grade) |
| 80 to 89.9 | Easy (6th grade) |
| 70 to 79.9 | Fairly easy (7th grade) |
| 60 to 69.9 | Standard (8th–9th grade) |
| 50 to 59.9 | Fairly difficult (10th–12th) |
| 30 to 49.9 | Difficult (college level) |
| Below 30 | Very difficult (professional) |
Four runs, checked independently
Each row was run through the calculator and then recomputed with a separate implementation of the same two formulas; the figures agreed. The third text is one 13-word sentence of long Latinate words, written twice. Its raw ease score is −183.8, shown as 0.0 after clamping, with a grade of 42.1.
| Text | Words | Sentences | Syllables | Ease | Grade | Label |
|---|---|---|---|---|---|---|
| Plain language helps readers. Short sentences are easy to follow. Most people scan a page before they read it. Use clear headings and common words. | 25 | 4 | 35 | 82.1 | 3.4 | Easy (6th grade) |
| The quick brown fox jumps over the lazy dog. This sentence contains every letter… (the default sample) | 32 | 4 | 62 | 34.8 | 10.4 | Difficult (college level) |
| Notwithstanding considerable organisational complexity, interdepartmental communication… (written twice) | 26 | 2 | 116 | 0.0 (clamped) | 42.1 | Very difficult (professional) |
| Stop! Look! Listen! The train is coming fast and you must move now before it is too late for everyone here. | 21 | 4 | 26 | 96.8 | 1.1 | Very easy (5th grade) |
Where syllable counting goes wrong
The rule counts groups of consecutive vowels, treats y as a vowel, and drops one syllable for a silent final e unless the word ends in a consonant plus le. Each word below was tested inside a 12-word sentence and its count read back from the Syllables row. Words with vowels that split into separate sounds are undercounted, and endings such as -ed or a final e after several vowels are overcounted. Numerals such as 1234 contribute zero syllables while still counting as words.
| Word | Tool | Usual | Result |
|---|---|---|---|
| table, simple, people | 2 | 2 | Correct |
| fire, queue, rhythm | 1 | 1 | Correct |
| area, idea | 2 | 3 | Undercounted |
| create, poem, science, quiet | 1 | 2 | Undercounted |
| business, somewhere | 3 | 2 | Overcounted |
| used, jumped | 2 | 1 | Overcounted |
Where sentence counting goes wrong, and sensible use
A six-line list of short promises with no full stops (Fast shipping, Easy returns and so on) is 12 words read as a single sentence, giving ease 39.6 and grade 10.7 although every line is simple. A sentence full of abbreviations and decimals (Dr. Smith measured 3.5 mg of the compound e.g. the sample, i.e. the control, on Jan. 5…) has 22 words but is split into 8 sentences, giving ease 100.0 and grade 0.0. Check the Sentences row before trusting a score, and use the tool comparatively: score two drafts of the same passage and see which moves the way you intended. It cannot judge vocabulary, structure or correctness.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →