What is a readability grade?
A readability grade estimates how hard a piece of text is to read, usually as the school grade or reading age needed to follow it comfortably, worked out from sentence length and word length.
The Flesch–Kincaid grade level
The best-known readability formula turns average sentence length and average syllables per word into a US school grade:
Grade = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59
A result of 8 means a typical 13- or 14-year-old could follow the text. Most business writing for a general audience does well between 7 and 10.
What a readability score can and cannot tell you
A readability score is a drift signal, not a target. It notices when sentences get long and words get heavy, but it cannot tell whether the text is clear, accurate or interesting, and short sentences can still confuse. Use it to catch the paragraph that crept up to grade 16, not to grind everything down to grade 5.
Readability for social media
Each channel tolerates a different level, and a social post is read in a scroll. AI Powered Content Repurposing grades each asset against its channel before it ships, because a sentence that works in a newsletter can be too long for a post.
How to improve readability
- Split sentences that carry two ideas.
- Swap long words for short ones where the meaning survives: use rather than utilise.
- Put the point first and the qualification after.
- Cut phrases that do no work, such as “in order to” and “the fact that”.
Last reviewed 2026-11-01.