Flesch-Kincaid Readability Score Calculator

A Flesch-Kincaid readability calculator scores how easy your text is to read. It runs two classic formulas on the paste below: Flesch Reading Ease, a 0–100 score where higher is easier, and the Flesch-Kincaid Grade Level, which shows the US school grade a reader needs to understand the text. Both are standard readability index tools used by writers, editors, and publishers to target plain, clear language.

Flesch Reading Ease runs from 0 to 100. Everyday prose usually lands between 60 and 70, which corresponds to plain English that a 13- to 15-year-old can read comfortably. A score of 80 or higher reads like simple children's writing; below 30 sits around college level and above. The "right" score depends on your audience — a blog aimed at general readers should target the 60–70 band, while a legal or technical document may sit much lower.

The calculator measures your text and applies the two Flesch-Kincaid formulas. Flesch Reading Ease is based on average words per sentence and average syllables per word: 206.835 minus 1.015 × (words ÷ sentences) minus 84.6 × (syllables ÷ words). The Flesch-Kincaid Grade Level formula is 0.39 × (words ÷ sentences) plus 11.8 × (syllables ÷ words) minus 15.59. Short sentences and short words are the fastest way to raise a Flesch reading ease score and lower the grade level.

Paste or type your text into the box, and the score updates as you type. The result shows your Flesch Reading Ease score, the Flesch-Kincaid Grade Level, and the raw word, sentence, and syllable counts behind them. Because everything runs in your browser, your text never leaves your device.