Flesch-Kincaid Readability Calculator

Flesch Reading Ease score ranges:

• ·90–100: Very easy (5th grade)
• ·80–90: Easy (6th grade)
• ·70–80: Fairly easy (7th grade)
• ·60–70: Standard (8th–9th grade) — target for most web content
• ·50–60: Fairly difficult (10th–12th grade)
• ·30–50: Difficult (college level)
• ·0–30: Very difficult (college graduate)

Flesch-Kincaid Grade Level targets:

• ·General web content: Grade 6–8
• ·Healthcare information: Grade 6 or below (health literacy standards)
• ·Legal content: Grade 12+ is common but Grade 8–10 is more accessible
• ·Children's content: Grade 3–5

Quick improvements:

Split sentences longer than 25 words. Replace three-syllable words with one- or two-syllable synonyms where meaning is not lost. These two changes alone raise most texts significantly.

Flesch-Kincaid vs Gunning Fog Index:

Gunning Fog counts "complex words" (three or more syllables) rather than average syllables per word. It tends to score slightly higher (harder) than Flesch-Kincaid for technical writing because it directly penalizes polysyllabic words. Both formulas are English-specific and validated for similar text types.

Flesch-Kincaid vs Coleman-Liau:

Coleman-Liau uses character counts instead of syllable counts, making it language-independent for European languages. It correlates well with Flesch-Kincaid for English text and may be more reliable for texts with many unusual words where syllable counting is ambiguous.

The Flesch-Kincaid readability formulas are the most widely used readability metrics in education, publishing, journalism, and content marketing. There are two related scores: the Flesch Reading Ease score (a 0–100 scale where higher is easier) and the Flesch-Kincaid Grade Level (a U.S. grade level estimate where lower means more accessible).

Both scores are calculated from the same two variables: average sentence length and average number of syllables per word. Long sentences with polysyllabic words produce low Reading Ease scores and high Grade Level numbers. Short sentences with simple words produce the opposite.

This calculator runs both formulas instantly on any text you paste. Web content targeting a general audience should aim for a Reading Ease score above 60 (roughly the level of a popular magazine) and a Grade Level at or below 8th grade. Technical documentation, academic writing, and legal content legitimately scores lower — the tool shows your score so you can assess it against your specific audience, not a universal standard.