Flesch Reading Ease Calculator

Enter the number of words, sentences and syllables in a passage and this calculator returns its Flesch Reading Ease score, the reading level it corresponds to, and the two averages that drive the score: words per sentence and syllables per word. Writers, editors, teachers and compliance teams use it to check that web copy, letters, policies or classroom texts suit their readers.

The score only measures sentence length and word length. It cannot tell whether a text is well organized, accurate or uses familiar words — "the cat sat on the mat" and a string of short, obscure words can score the same. Treat it as a quick signal, not a verdict.

You need three counts. Word and sentence counts come from any word processor or the word and character counter; syllables are harder to count by hand, so sample a 100-word passage and scale up. This page also covers reading level: the table below maps scores to US school grades, and the Flesch–Kincaid grade formula is given for anyone who needs a grade number directly.

Rudolf Flesch published the formula in 1948 ("A New Readability Yardstick", Journal of Applied Psychology). In 1975 J. Peter Kincaid and colleagues re-derived it for the US Navy as the Flesch–Kincaid Grade Level: 0.39 × (W ÷ S) + 11.8 × (Y ÷ W) − 15.59, which gives a US school grade instead of a 0–100 score. Both were built for English prose; they do not transfer to other languages, and they give odd results for lists, code, poetry or very short texts under about 100 words.

Flesch's original interpretation table, with the approximate US school grade and the kind of text that typically falls in each band. The calculator's label groups the two bands from 70 to 90 together as "Easy".

The two terms in the formula tell you where the points are. Each extra word in the average sentence costs about 1 point; each extra 0.1 syllables per word costs about 8.5 points — so word choice matters more than it looks.

• Split long sentences. Going from 25 to 15 words per sentence adds about 10 points.
• Swap long words for short ones: "use" for "utilize", "help" for "facilitate", "buy" for "purchase".
• Cut nominalizations: "we decided" instead of "we made a decision".
• Keep necessary technical terms. If readers need the word "insulin", keep it and shorten the sentence around it instead.

After editing, re-count with the word and character counter and recheck — the score should move in the direction the averages predict.

Tools disagree on counts, which is why two readability checkers can report different scores for the same text. Pick one method and stick with it when comparing drafts.

• Syllables: count vowel sounds, not vowels. "Time" is 1, "reading" is 2, "calculation" is 4. Numbers count as the spoken word ("2026" can be 4 or more), so many tools skip them.
• Sentences: headings and list items without full stops are often merged into the next sentence by software, which lowers the score. Counting each bullet as a sentence is more realistic for web pages.
• Sampling: for long documents, take three 100-word samples from the start, middle and end and average the three scores with the average calculator.