About
Flesch Reading Ease: 0-100 score. Higher = easier. 90-100: 5th grade. 60-70: 8th-9th grade (standard). 30-50: college. 0-30: very difficult. Used by Microsoft Word and many tools. Key driver: short sentences + simple words.
Formula
Frequently asked questions
What is the Flesch Reading Ease formula?
The Flesch Reading Ease score is 206.835 minus 1.015 times the average sentence length (words per sentence) minus 84.6 times the average number of syllables per word. The result is a number on roughly a 0 to 100 scale where higher means easier to read. The two levers are sentence length and word complexity: short sentences and short words raise the score, long sentences and polysyllabic words lower it.
What is a good Flesch Reading Ease score?
For general web and business writing, aim for 60 to 70, which maps to a US 8th-to-9th-grade reading level that most adults handle comfortably. Scores of 90 to 100 read at a 5th-grade level (very easy), 30 to 50 are college level, and below 30 are very difficult, typical of academic or legal text. Plain-language guidelines often target 60 or above.
What is the difference between Reading Ease and Grade Level?
They use the same inputs but scale them in opposite directions. Flesch Reading Ease gives a 0 to 100 score where higher is easier. The Flesch-Kincaid Grade Level converts the same sentence-length and syllable data into a US school grade, so 8.0 means an eighth grader can read it. Reading Ease is handy for a quick easy-or-hard read; Grade Level is handy when you need to hit a specific audience grade.
How can I improve my Flesch Reading Ease score?
Shorten sentences and swap long words for short ones, since those are the only two variables in the formula. Split compound sentences at conjunctions, cut filler clauses, and prefer use over utilize or help over facilitate. Bullet lists, active voice, and one idea per sentence all push the average sentence length down and lift the score.
Is a higher Flesch score always better?
Not always. The right target depends on the audience and purpose. A children's book or a public health notice should score high (easy), but a legal contract, scientific paper, or specialist manual is expected to score lower because the vocabulary is unavoidably technical. Match the score to the reader rather than chasing the highest possible number.
About the Flesch Reading Ease score
The Flesch Reading Ease test, developed by Rudolf Flesch in 1948, rates how hard a passage of English is to read on a scale of roughly 0 to 100. A higher score means easier reading. It is one of the most widely used readability formulas in the world, built into Microsoft Word, government plain-language standards, and countless content tools. The appeal is its simplicity: it depends on just two measurable things, how long your sentences are and how many syllables your words carry.
Because the formula only sees sentence length and syllable count, it is a proxy for difficulty rather than a judge of meaning. A passage of short, common words in short sentences will score as easy even if the ideas are subtle, and dense technical writing will score low even when it is clear to its intended expert reader. Used sensibly, it is an excellent quick gauge of whether your writing matches your audience.
How the score is calculated
FRE = 206.835 - 1.015 x (total words / total sentences)
- 84.6 x (total syllables / total words)
Higher score = easier to read
Average sentence length and syllables per word
are the only two inputs.
- Words per sentence is the average sentence length. Long sentences cut the score.
- Syllables per word measures word complexity. Polysyllabic words cut the score.
- 206.835 is the constant that anchors the scale near 0 to 100 for typical English.
- The related Flesch-Kincaid Grade Level reuses the same two inputs but outputs a US school grade instead.
Worked example
Take a passage of 100 words in 5 sentences with 150 syllables.
- Average sentence length: 100 words / 5 sentences = 20 words per sentence.
- Syllables per word: 150 / 100 = 1.5.
- Apply the formula: 206.835 minus (1.015 x 20) minus (84.6 x 1.5).
- Compute: 206.835 minus 20.3 minus 126.9 = 59.6.
Score bands and reading level
| Score | Reading level | Example |
|---|---|---|
| 90 to 100 | 5th grade, very easy | Children's books, simple instructions |
| 70 to 90 | 6th to 7th grade, easy | Conversational web copy |
| 60 to 70 | 8th to 9th grade, standard | Most news and business writing |
| 50 to 60 | 10th to 12th grade | Detailed articles, manuals |
| 30 to 50 | College | Academic and professional prose |
| 0 to 30 | Very difficult | Legal documents, scientific papers |
Common pitfalls
- Chasing the highest score. The right target depends on the audience; a contract is meant to score low.
- Trusting syllable counts blindly. Automated syllable counting is an estimate; unusual names and acronyms can skew it.
- Ignoring meaning. The formula rewards short words and sentences, not clear logic. A high score can still be confusing.
- Comparing across languages. The constants are calibrated for English; the score is not valid for other languages.
- Confusing Reading Ease with Grade Level. They scale in opposite directions, so a high Ease score is a low grade.