Flesch-Kincaid grade level calculator

The formula

0.39 × (words / sentences) + 11.8 × (syllables / words) − 15.59

Output is a US grade level. 8.2 means “an average 8th-grader can read this.” The formula was developed by Peter Kincaid for the US Navy in 1975 to ensure training manuals matched the education level of enlisted personnel.

Grade level by audience

• Grades 1–6: Children, early ESL learners, accessibility-first content.
• Grades 7–9: The sweet spot for consumer writing. Most successful blogs and newsletters target this range.
• Grades 10–12: Professional content, B2B blogs, journalism.
• Grades 13+: Academic, technical, specialist.

Where Flesch-Kincaid is required

• US military— all technical manuals must score at grade 8 or below.
• US Department of Defense— uses Flesch-Kincaid for training and equipment documentation.
• Florida insurance contracts— must score grade 6 or below by state law.
• Microsoft Word— built-in readability statistics include Flesch-Kincaid.
• Plain-language government writing(US, UK, AU) — commonly targets grade 8 maximum.

Improving your Flesch-Kincaid score

The formula rewards: shorter sentences and shorter words. To drop your grade level by 2–3 points:

• Break sentences over 25 words into two. Average effect: −1.5 grade points.
• Replace 4+ syllable words with shorter equivalents. Each swap drops the score by ~0.1–0.3.
• Remove filler phrases (“in order to,” “at this point in time”).
• Convert nominalizations: “made a decision” → “decided.”