Flesch-Kincaid Readability Calculator

About this calculator

This calculator runs your text through two related formulas developed for the U.S. Navy in the 1970s. The Flesch Reading Ease score is 206.835 − 1.015×(words/sentences) − 84.6×(syllables/words), producing a 0–100 scale where higher means easier to read — 90+ is roughly 5th-grade prose, 30 or below is closer to dense academic or legal writing. The Flesch-Kincaid Grade Level converts the same sentence-length and syllable-density inputs into a U.S. school grade: 0.39×(words/sentences) + 11.8×(syllables/words) − 15.59.

Technical writers, UX copywriters, and journalists use these scores to keep instructions and articles accessible to a general audience, while Microsoft Word and Google Docs still ship the same formulas under "readability statistics." Government agencies and insurers in the U.S. often mandate a specific Flesch-Kincaid grade level for consumer-facing forms and plain-language disclosures.