The Flesch-Kincaid Readability Calculator is a tool used to evaluate the reading level of a given text. It calculates how many years of education a reader would typically need to understand the content. This is particularly useful for writers, teachers, publishers, and content creators who want to make sure their material is appropriate for their intended audience.
It helps determine if a document is suitable for elementary students, high schoolers, college-level readers, or professionals. The calculator is widely used in education, government documents, business communication, and online publishing to improve clarity and accessibility.
Formula of Flesch Kincaid Readability Calculator
Flesch-Kincaid Grade Level = (0.39 × ASL) + (11.8 × ASW) − 15.59
Where:
ASL = Average Sentence Length = Total Words ÷ Total Sentences
ASW = Average Syllables per Word = Total Syllables ÷ Total Words
To compute the readability score using this formula, follow these steps:
- Count the total number of words in the text.
- Count the total number of sentences.
- Count the total number of syllables.
- Calculate ASL by dividing total words by total sentences.
- Calculate ASW by dividing total syllables by total words.
- Plug ASL and ASW into the formula to get the Flesch-Kincaid Grade Level.
The result will indicate the U.S. school grade level needed to comprehend the text.
Readability Reference Table
| Grade Level | Reader Age | Description of Text Complexity |
|---|---|---|
| 1–5 | 6–10 | Very easy: children’s books, beginner material |
| 6–8 | 11–13 | Easy: middle school content |
| 9–12 | 14–17 | Moderate: high school texts |
| 13–16 | 18–22 | Advanced: college-level and technical writing |
| 17+ | 23+ | Very difficult: professional or academic works |
This table offers a general guide to match text complexity with reading ability. Writers can use it to revise their material to suit their audience better.
Example of Flesch Kincaid Readability Calculator
Imagine a passage has the following characteristics:
- Total Words: 180
- Total Sentences: 6
- Total Syllables: 270
Step 1: ASL = 180 ÷ 6 = 30
Step 2: ASW = 270 ÷ 180 = 1.5
Step 3: Apply the formula:
Flesch-Kincaid Grade Level = (0.39 × 30) + (11.8 × 1.5) − 15.59
= 11.7 + 17.7 − 15.59
= 13.81
This means the content is suitable for college-level readers, likely around the freshman or sophomore level.
Most Common FAQs
The Flesch Reading Ease score ranges from 0 to 100, with higher scores indicating easier readability. The Flesch-Kincaid Grade Level expresses the difficulty in terms of U.S. school grade levels. Both use similar inputs but give different types of output.
It depends on your audience. If your content is for the general public, aim for a grade level between 6 and 8. For academic or professional audiences, higher scores may be acceptable.
Yes. Use shorter sentences and simpler words. Reducing syllables and sentence complexity can lower the grade level, making your content easier to understand.