Flesch Reading Ease Calculator: Score Any Text Free

Paste any text to get its Flesch Reading Ease score, its Flesch-Kincaid grade level and an approximate reading age, with the long sentences pulled out so you know what to fix first. Both scores come from just two numbers: how many words you put in each sentence and how many syllables you put in each word. That is why shortening sentences almost always lifts your score faster than hunting for simpler synonyms.

How the Flesch scores are calculated

The Flesch Reading Ease formula, published by Rudolf Flesch in 1948, is 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words). Higher is easier. Most everyday text lands between 0 and 100, though very short, simple sentences can push it above 100. The Flesch-Kincaid grade level, adapted for the US Navy in 1975, uses the same two inputs weighted differently: 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. It gives a US school grade, so the reading age shown here is that grade plus five to six years.

Why the numbers can differ between checkers

Every readability tool has to guess where sentences end and how many syllables each word has, and none of them guess identically. This one counts vowel groups, drops most silent final e's and treats each line break as a sentence end, so bulleted lists and headings score as short sentences. Common abbreviations such as e.g., i.e. and etc. are not treated as full stops. Expect a score within a few points of Microsoft Word or Hemingway rather than an exact match, and compare drafts in the same tool. Reading time assumes 238 words per minute, the average silent reading rate for non-fiction that Marc Brysbaert found in a 2019 review of 190 studies.

Using readability in UX and conversion work

A score is a smoke alarm, not a style guide. It cannot tell whether your words are the ones your users actually use, or whether the page answers their question. Use it to catch the paragraph that has drifted into 40-word sentences, then check comprehension properly with real people: our usability testing guide covers how, and the usability test sample size calculator tells you how many sessions to run. If you rewrite a landing page for clarity, treat it as a hypothesis and measure it with the A/B test significance calculator rather than assuming simpler copy converts better.