Flesch-Kincaid Grade Level Calculator

It estimates the U.S. school grade needed to read the text on a first pass. A grade of 8 means an average eighth grader should follow it comfortably, while a grade of 13 or more points to college-level reading. Lower numbers mean easier text.

The formula is 0.39 times the average words per sentence, plus 11.8 times the average syllables per word, minus 15.59. Longer sentences and longer words both push the grade up, so the two biggest levers on your score are sentence length and word length.

The tool renders the full readability panel so you get context, not just one number. The Flesch-Kincaid Grade is the card highlighted in green, and alongside it you see Flesch Reading Ease plus the Gunning Fog, Coleman-Liau, ARI and SMOG grade indices for comparison.

A word is a run of letters, digits or underscores, so hyphenated pairs count as two words. A sentence is a group of ending marks such as a period, question mark or exclamation point, with a minimum of one sentence for any non-empty text. That floor stops a heading with no full stop from dividing by zero.

Each word is lowercased, then runs of consecutive vowels (a, e, i, o, u and y) are counted as syllables. A silent trailing e is dropped in most cases, and every word is floored at one syllable. It is a heuristic estimate, not a dictionary lookup, so odd spellings can be off by one.

No. Because syllables are estimated by a rule rather than looked up, unusual or technical words can shift the count slightly. Treat the grade as a close approximation that is reliable for comparing drafts, not as an exact phonetic measurement.

For general web content, marketing and email, grade 7 to 9 keeps most adults reading easily. Government and health guidance often targets grade 6 to 8. Academic or legal writing naturally sits higher, so match the target to your audience rather than chasing a single number.

The formula assumes enough words and sentences to average out. A handful of words, or a single very long or very short sentence, can produce a grade that swings high or dips below zero. Paste a full paragraph or more for a grade you can trust.

Yes. The grade and every other score are computed in your browser as you type. Nothing is uploaded, logged or stored, so even sensitive drafts never leave your device.