Reading Level Calculator
Readability formulas turn a few counts about your text into a clear measure of how hard it is to read. This calculator applies the Flesch Reading Ease and Flesch-Kincaid grade-level formulas, both fixed published equations used widely by U.S. agencies, to the words, sentences, and syllables you provide. It returns the Reading Ease score, the grade level, the average words per sentence, and the average syllables per word. Because the formulas use constant coefficients, the result is fully determined by your three inputs.
Readability formulas
Words per sentence = words / sentences
Syllables per word = syllables / words
Reading Ease = 206.835 - 1.015 * words per sentence - 84.6 * syllables per word
Grade level = 0.39 * words per sentence + 11.8 * syllables per word - 15.59
Both equations have fixed coefficients from the original Flesch and Flesch-Kincaid research. A higher Reading Ease means easier text; a higher grade level means harder text. The calculator applies the constants exactly.
Reading level context
- Reading Ease near 60 to 70 is considered plain, everyday English.
- Flesch-Kincaid grade level maps to U.S. school grades.
- The formulas were developed under U.S. Navy and government research.
- Shorter sentences and shorter words both raise the Reading Ease score.
- Plain-language guidance often targets around an eighth-grade level.
Reading level: frequently asked questions
What is the Flesch Reading Ease score?
The Flesch Reading Ease score rates how easy a text is to read on a 0 to 100 scale, where higher is easier. It is computed as 206.835 minus 1.015 times the average words per sentence minus 84.6 times the average syllables per word. Scores around 60 to 70 are considered plain English.
What is the Flesch-Kincaid grade level?
The Flesch-Kincaid grade level estimates the U.S. school grade needed to understand a text. It is 0.39 times words per sentence plus 11.8 times syllables per word minus 15.59. A result of 8 means an eighth-grade reading level. These formulas were developed for the U.S. Navy and are widely used by U.S. agencies.
How do I count syllables, words, and sentences?
Count every word in your sample, the number of sentences (units ending in a period, question mark, or exclamation point), and the total syllables across all words. Many word processors report words and sentences automatically; syllables you can estimate by counting vowel sounds. Enter the three totals.
Why do these formulas need no real-world source figure?
The Flesch and Flesch-Kincaid formulas are fixed, published equations with constant coefficients. The calculator applies those exact constants to the counts you provide, so no empirical figure is assumed or estimated. The result is fully determined by your three inputs.
What reading level should I aim for?
U.S. plain-language guidance often suggests writing for around an eighth-grade level for general audiences, which corresponds to a Reading Ease near 60 to 70. Technical or legal writing scores lower (harder). Aim for the level that matches your audience, then revise to shorten sentences and words.
Official sources
- U.S. General Services Administration: Plain language readability guidance.
- U.S. National Institutes of Health: Clear communication and readability.
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.