Flesch–Kincaid grade level calculator
Calculate the U.S. grade-level estimate from sentence length and syllable load.
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Grade level
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The grade estimates the U.S. school year that might be comfortable with the sentence length and syllable load. It is not a placement test.
- Syllables (estimate)
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- Words per sentence
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- Syllables per word
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How to use the grade calculator
- Paste the prose the reader will see, not your notes about it. Include a representative stretch, ideally 100 words or more.
- Read the large grade first. The Reading Ease number is secondary here so you can compare, and its scale lives on the Reading Ease page.
- If the grade is higher than you wanted, the ingredients on the page show whether sentences or syllables did it.
- Do not report the grade as a child’s reading age. Report it as a Flesch–Kincaid grade level, and link the formula if someone asks.
The 1975 formula
The grade used here is the Flesch–Kincaid grade level from the U.S. Navy study by Kincaid, Fishburne, Rogers, and Chissom in 1975. It revises Flesch’s earlier work into a school-year scale:
0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59
“The cat sat on the mat.” has 6 words, 1 sentence, and 6 syllables. That is 0.39 × 6 + 11.8 × 1 − 15.59, or -1.40 before you round the display. The page shows -1.4 and the label “early elementary,” because a negative grade is not a negative school year. The raw figure stays on screen. Clipping it to zero would look tidier and would lie about the arithmetic.
Words and sentences follow the word counter and thesentence counter. Syllables follow the same vowel-group estimate documented on thereadability checker. If another tool prints a different grade for the same paragraph, compare those three inputs before you assume the coefficients differ. They are often the same coefficients and a different syllable list.
What the labels are willing to say
| Rounded grade | Label on this page |
|---|---|
| Under 1 | Early elementary |
| 1–12 | About that U.S. school year (1st, 2nd, 3rd, and so on) |
| 13–16 | College level |
| 17 and above | Graduate level |
These labels are a reading aid. They are not a transcript. A grade near 8 means the sentence length and the syllable load look like the materials that formula associated with that year. It does not mean an eighth-grader will understand the argument, and it does not mean a college graduate will find a grade-14 paragraph elegant. Time on the page is a separate estimate: use reading time when the question is minutes, and keep this page when the question is the grade.
The Reading Ease calculator answers “how easy is the surface?” on a scale where higher is easier. Do not subtract the grade from 100 and call it Reading Ease. The equations are different.
Limitations
- This is not an educational assessment, a medical claim, or a finding that a contract was readable.
- Short passages are unstable. The cat sentence is a formula check, not a document score.
- Vocabulary difficulty beyond syllable count is invisible. So is structure across paragraphs.
- The calculator does not simplify the text. A lower grade that deletes necessary terms is not automatically better writing.
Questions people ask
Is a grade of 8 a target I should hit?
Many plain-language programs aim near grades 7 to 9 for the general public. That is a house style, not a law, and it is not a reason to drain a specialist text of the terms it needs. Match the grade to the audience you named, then read the paragraph yourself.
Can the grade be negative?
Yes. The 1975 formula is a straight line, not a school transcript. “The cat sat on the mat.” lands below zero because it is one short sentence of one-syllable words. The label says early elementary, and the number stays visible so the formula is not hidden.
Does this place a student in a grade?
No. Kincaid and colleagues built the grade to describe how difficult training text was, using U.S. school years as the unit. It does not know the reader. Do not use it as an assessment, a diagnosis, or a legal finding about whether a notice was understandable.
Why does the Reading Ease page exist as well?
Reading Ease is the earlier 0–100-style score. Some briefs ask for it by name. The grade asks a different question and uses different coefficients. Reporting one when you were asked for the other is a good way to confuse an editor.
Is the draft uploaded to calculate the grade?
No. The grade is calculated in the browser. The draft is not sent to TextStats.