CalcLake

Readability Checker

Score how easy your writing is to read.

Text & WritingLast updated August 2026
Flesch Reading Ease73.8
Flesch-Kincaid grade5.8
Gunning Fog index8.1
Words23
Sentences2
Avg words / sentence11.5
0306070100
Very confusingDifficultStandardEasy

Fairly easy to read.

How to use it

  1. 1Paste an article, essay, or blog post into the box.
  2. 2Scores recalculate instantly as you edit the text.
  3. 3Read the Flesch Reading Ease, Grade Level, and Gunning Fog scores, plus the plain-English summary.
  4. 4Turn on "Highlight long sentences and complex words" to see exactly which sentences and words to simplify.

Supported formats & limits

No character limit — works with anything from a sentence to a full document.

Example

Short, simple sentences push the Flesch Reading Ease score up toward 100 (very easy); long sentences packed with multi-syllable words push it down toward 0 (very confusing). The gauge and grade-level scores update as you type — turn on the highlight view to see exactly which sentences and words are dragging the score down.

How it works

The Flesch Reading Ease and Flesch-Kincaid Grade Level scores are computed from your average sentence length and average syllables per word, using the standard published formulas. Gunning Fog adds in the share of “complex” words (three or more syllables). Syllables are estimated with a vowel-grouping heuristic rather than a dictionary, so counts are close but not always exact, and sentences are split on punctuation with a decimal-number exception (“3.14” won't be miscounted as two sentences) — though abbreviations like “Dr.” can still split early. The highlight view reuses these same counts to mark sentences over 20 and 30 words and underline individual complex words directly in your text.

Frequently asked questions

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