Paste your text and see how easy it is to read. You get the Flesch Reading Ease score and the Flesch-Kincaid grade level live, plus average sentence length, syllables per word, and a clear statement of what school grade can comfortably read your writing.
Typical guidance, not rules — the right level is whatever your actual audience reads comfortably.
📌 Formulas measure only sentence length and word length — not whether your ideas are clear. Syllables are counted with a heuristic plus an exceptions dictionary, so scores may differ slightly from other tools. English text only.
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What the formulas actually measure
Both scores come from Rudolf Flesch's work in the 1940s and its US Navy revision in the 1970s, and both use exactly two ingredients: how long your sentences are (words per sentence) and how long your words are (syllables per word). Flesch Reading Ease is 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words), reported on a 0–100 scale where higher is easier. Flesch-Kincaid Grade re-maps the same inputs onto US school grades: 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59.
That means the formulas measure the surface of your prose, not the clarity of your ideas. A logically muddled text made of short common words scores beautifully; a crisp, well-organized argument full of necessary technical terms scores poorly. The scores correlate with reading difficulty across large samples — which is why they are embedded in everything from Word to US state insurance law — but for any single text they are a smoke detector, not a judge.
How to improve a score honestly
Two levers move the score, and used honestly both make real text better. First, sentence length: hunt for sentences carrying two or three ideas and give each idea its own sentence. Aim for an average of 15–20 words per sentence with plenty of variation — not a hard cap. Second, word length: prefer the common short word when it says the same thing ("use" over "utilize", "help" over "facilitate"), and keep the long word when it is the precise one.
The limit of this game is obvious once you see it: the formula cannot tell simplified prose from chopped prose. Five-word sentences all the way down will score in the 90s and read like a ransom note. Edit for the reader, then use the score to verify the trend — never the other way around.
Frequently asked questions
For most general-audience writing, 60–70 is the sweet spot — plain English an average 8th–9th grader can read. Above 80 reads as very easy and conversational; below 50 starts to feel like academic prose. There is no universally "good" score, though: expert documentation can legitimately sit at 30–50, while ad copy often aims for 70 or higher.
Around 7th–8th grade (Flesch-Kincaid Grade 7–8, Reading Ease roughly 60–70). This is not about assuming readers are uneducated — studies consistently show even highly educated readers prefer and skim plain text faster online, where attention is short. Newspapers, government plain-language guidelines, and most content-marketing teams converge on the same range.
They use the same two ingredients — average sentence length and average syllables per word — but report on different scales. Flesch Reading Ease gives a 0–100 score where higher means easier. Flesch-Kincaid Grade Level converts the same inputs into a US school grade, where lower means easier: a grade of 8.0 means an average 8th grader can read the text. A Reading Ease of 65 and a Grade of about 8 describe roughly the same text.
No. Both formulas were calibrated on English: the constants (206.835, 84.6, 11.8 and so on) were fitted to English sentence and word lengths, and the syllable counter uses English pronunciation rules. Running Finnish, Spanish, or German text through them produces numbers, but the numbers are meaningless — languages with long compound words score as "very difficult" regardless of actual clarity. Language-specific variants exist for several languages.
Yes — and up to a point that genuinely helps readers. But the formula only sees sentence length and word length, so you can game it: chopping every sentence to five words yields a great score and choppy, robotic prose. Use the score as a smoke detector, not a target. If it flags grade 14 for a general audience, look for sentences doing too much work and jargon with simpler equivalents — then judge the rewrite by ear.