Reading Level Analyzer
Flesch Reading Ease and Flesch-Kincaid Grade Level for any text.
Overview
Compute the Flesch Reading Ease and Flesch-Kincaid Grade Level scores for any English passage. The Reading Ease score runs from 0 (very hard) to 100 (very easy); the Grade Level approximates the US school grade a reader needs to comfortably handle the text.
Content writers tuning blog posts for accessibility, marketing teams checking email readability, educators picking passages for a target age group, and authors auditing their own prose all rely on readability metrics. Major style guides recommend keeping general-audience writing around grade 7–9 for the broadest comprehension.
How it works
Both scores use two inputs: average sentence length (words per sentence) and average syllables per word. Flesch Reading Ease = 206.835 − 1.015 × (words/sentence) − 84.6 × (syllables/word). Higher scores mean easier text. The Flesch-Kincaid Grade Level applies a different weighting — 0.39 × (words/sentence) + 11.8 × (syllables/word) − 15.59 — and outputs a number that maps roughly to US grade levels.
Syllable counting uses heuristics (vowel-group rules with adjustments for silent E, common diphthongs, and word endings) and is the main source of small differences between tools.
Examples
Passage: "The cat sat on the mat. It was a sunny day."
Flesch Reading Ease: 116.1
Flesch-Kincaid Grade: 0.5
(Very easy — early elementary.)
Passage: A typical newspaper paragraph
Flesch Reading Ease: 60
Flesch-Kincaid Grade: 8
(Standard — accessible to most adults.)
Passage: Dense academic prose
Flesch Reading Ease: 30
Flesch-Kincaid Grade: 14
(Hard — college-level.)
FAQ
What's a "good" Reading Ease score?
For general-audience writing, aim for 60–70. Below 50 starts to feel academic; above 80 feels childlike.
Are these scores reliable for technical content?
They're rougher there. Technical jargon inflates syllable counts and short sentences hide complexity. Use them as a sanity check, not a verdict.
What's the difference between Flesch-Kincaid and other readability tests?
Flesch-Kincaid is one of several formulas (Gunning Fog, SMOG, Coleman-Liau, ARI). They use slightly different inputs but mostly agree on which passages are harder.