About the Readability Score Calculator
This readability score calculator measures how easy your writing is to read using six established formulas: Flesch Reading Ease, the Flesch-Kincaid Grade Level, the Gunning Fog Index, the SMOG Index, the Coleman-Liau Index and the Automated Readability Index (ARI). Paste your text to get a score, a US school grade level and the statistics behind them — sentences, words, syllables and complex words.
Writers, marketers, teachers, UX writers and anyone producing public information use readability scores to make sure text suits its audience. Plain-language guidance for consumer and government content commonly targets roughly an 8th-grade level or a Flesch Reading Ease of about 60 or higher, while technical and academic writing usually scores harder.
Scores are estimates. Syllables are counted with a rule-of-thumb English heuristic rather than a dictionary: words of three letters or fewer always count as one syllable ("any" = 1), and two vowels side by side count as one ("liability" = 4 instead of 5). On typical prose this moves the scores by only a few points, but text full of unusual words, names or abbreviations can be further off, and the formulas only measure sentence and word length — not whether the ideas are clear. Use the numbers to spot long sentences and heavy vocabulary, then read the text aloud to judge the result.
With the default inputs, the flesch reading ease is 74.7. Change any value above to recalculate instantly.
How to use the readability score calculator
- 1Paste at least a few paragraphs of your text for a reliable score.
- 2Read the Flesch Reading Ease score and reading level.
- 3Compare the grade-level formulas with your audience.
- 4Shorten long sentences and replace long words, then check again.
Formula and method
All six formulas combine average sentence length with a measure of word difficulty. Flesch Reading Ease and Flesch-Kincaid use syllables per word; Gunning Fog and SMOG use the share of "complex" words with three or more syllables; Coleman-Liau and ARI use letters or characters per word, which is why they need no syllable counting. Flesch Reading Ease runs roughly 0–100 (higher is easier); the others estimate the US school grade needed to understand the text.
Words are runs of letters and digits, sentences end with ".", "!" or "?", and syllables are estimated without a dictionary: words of three letters or fewer count as one syllable; otherwise a silent final "e" or "es" (and "ed" unless it follows t or d) and a leading "y" are removed, and each group of one or two adjacent vowels (a, e, i, o, u, y) counts as one syllable, with a minimum of one. Because adjacent vowels are merged, words such as "liability", "radio" or "area" are under-counted, and short words such as "any" count as one. Gunning Fog is simplified here to count every 3+ syllable word as complex (the original excludes proper nouns and some suffixes), so it may read slightly high. The average grade is the mean of the five grade-level formulas.
- W
- Number of words
- S
- Number of sentences
- Sy
- Number of syllables
- C
- Complex words (3 or more syllables)
- L, S₁₀₀
- Letters and sentences per 100 words (Coleman-Liau)
- ch
- Letters and digits (ARI)
Worked examples
Plain-language finance tip
The 41 words in four sentences average 10.25 words per sentence and 59 ÷ 41 ≈ 1.44 syllables per word. Flesch Reading Ease = 206.835 − 1.015 × 10.25 − 84.6 × 1.439 ≈ 74.7, "fairly easy", and the Flesch-Kincaid grade is about 5.4.
Dense legal-style sentence
One 20-word sentence with an estimated 49 syllables (2.45 per word) scores about −20.7 on Flesch Reading Ease — far harder than typical academic prose, at a grade level above 21. Ten words such as "notwithstanding", "indemnify" and "utilization" have three or more syllables. A dictionary count gives a few more syllables ("liability" has five, "any" two), which would push the score even lower.
Very simple sentences
With one syllable per word and five words per sentence, the formulas go off the ordinary scale: Flesch Reading Ease is above 100 and the grade level is below zero, meaning the text is readable by early readers.
Frequently asked questions
What is a good Flesch Reading Ease score?+
For general audiences aim for 60–70 or higher, which corresponds to plain English that most 13–15-year-olds can read. Scores of 30–50 are typical of academic writing, and below 30 is very difficult, like legal text.
What is the difference between Flesch Reading Ease and Flesch-Kincaid?+
Both use words per sentence and syllables per word. Reading Ease gives a 0–100 score where higher is easier, while the Flesch-Kincaid Grade Level converts the same inputs into a US school grade, where lower is easier.
What grade level should I write at?+
Many plain-language guides recommend about 8th grade for content aimed at the general public, such as health and consumer information. Technical or professional audiences can handle higher levels, but shorter sentences still help.
Why do different readability formulas give different grades?+
Each formula measures difficulty differently — syllables, long words, or letters per word — and was calibrated on different reading material. Treat them as a range; the average grade gives a balanced single figure.
How can I improve my readability score?+
Split long sentences, use shorter common words instead of long ones ("use" instead of "utilize"), prefer active voice and cut filler phrases. Aim for an average of about 15–20 words per sentence.