Readability Score Calculator
Score your writing with six readability formulas at once, plus a consensus grade level and the exact sentences to fix.
- Free, no account
- No watermark
- No usage limit
About the Readability Score Calculator
Most free readability checkers hand you one number, usually Flesch Reading Ease, and leave you to figure out what to do with it. This one runs all six formulas editors actually use (Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, and the Automated Readability Index) at the same time, averages the grade-level scores into a single consensus grade you can trust, then points straight at the sentences dragging that grade up. Paste a draft, an email, a policy notice, whatever you are about to publish, and the scores appear the moment you stop typing, with no button to press, no upload and no account.
Why six instead of one? Because every single one of these formulas has a blind spot, and a checker that reports just one is handing you that blind spot as your answer. Flesch and Flesch-Kincaid lean on a syllable estimate. Gunning Fog and SMOG mostly care about long words. Coleman-Liau and ARI ignore syllables and count letters instead. On the same paragraph they can land a grade or two apart, so the average across all of them is steadier than any one score alone. That average is the number the tool shows biggest, and it is the one to quote when someone just wants a straight answer.
The reason any of this matters is blunt. The average American adult reads at roughly a 7th to 9th grade level. Write above that and a chunk of your audience quietly clicks away, whether that is a customer skimming a product page or a patient trying to follow a dosage. Watching the grade drop as you cut a rambling sentence shows you, in one number, whether the writing got easier.
How to use
- Type or paste your text into the box, or drop a
.txtor.mdfile right onto it. Scores update live, so there is nothing to press. - Read the consensus grade first. It sits up top, big, and it is the average of the five grade formulas. When you want a single number, this is it.
- Set a target if you have one. Pick who you are writing for (grade 8 for a general audience, grade 12 for news) and the tool tells you whether you are there, or how many grades over.
- Look at the six scores together. Flesch Reading Ease is the one where higher means easier, and 0 to 100 is the range ordinary prose lands in rather than a limit the equation enforces, so a run of very short, very plain sentences can score above 100. The other five report a U.S. school grade. When they disagree, the spread is telling you whether your problem is long sentences or heavy vocabulary.
- Fix the hardest sentences. The tool lists the sentences pulling your grade up the most. Split one in two, drop a clause, and watch the numbers move.
What the six scores are telling you
The formulas fall into three natural groups, and knowing the group tells you what each one reacts to.
The two Flesch scores are the pair most people know. Same two ingredients, words per sentence and syllables per word, reported differently. Reading Ease is the ease score, higher is easier, and it is the one wired into Yoast and a lot of CMS plugins. Flesch-Kincaid runs the same math but returns a grade, and it is the number built into Microsoft Word and Google Docs. If an editor glances at one score, it is usually one of these.
Gunning Fog and SMOG go after long words on purpose. Both treat words of three or more syllables as the thing making text hard, so they reward cutting big vocabulary rather than long sentences. Fog is handy when your sentences are already tight but the words are still fancy. SMOG is the healthcare standard, because it was validated to predict full comprehension, exactly what you need on a consent form or a medication label.
Coleman-Liau and ARI take a different route. They skip syllables and count letters and characters, which a computer counts exactly instead of estimating, so they cross-check the other four. When the syllable-based and character-based scores agree, you can trust the read. If they disagree, an unusual word is probably throwing the syllable estimate off, and the real grade is somewhere between the two.
What actually moves the number
Strip away the constants and every formula watches the same three things.
Sentence length is the big lever. Every grade formula treats a longer average sentence as harder text, so breaking one 30-word sentence into two 15-word ones lowers every grade score and lifts Reading Ease at once. Aim for an average around 15 to 20 words, with enough variety that it does not read choppy.
Word length is next. "Use" beats "utilize," "help" beats "facilitate." Shorter words carry fewer syllables and fewer letters, so they move both the syllable-based and character-based scores. Then there are the long words, the three-plus syllable ones that Fog and SMOG punish hardest. You cannot cut them all, but swapping the ones that have a simpler synonym is the quickest way to bring those two down.
These levers overlap, so shorter sentences and plainer words lift all six together rather than trading one against another.
Who leans on which score
Content and marketing writers usually target a Reading Ease of 60 or higher to keep a broad audience. Readability is not a direct Google ranking factor, and Google staff have said so repeatedly in webmaster office hours over the years, but writing people can actually read holds attention longer, which helps in the ways that count. Teachers match material to a grade so it fits the class, the job these formulas were built for. Plain-language and legal writers hit mandated grades on government notices, terms, and consent forms. Healthcare writers reach for SMOG. And UX writers keep error messages and button copy low-grade so people get them instantly, under stress, on a small screen.
These scores come with a fair warning: they measure structure, not meaning. A paragraph can score "very easy" and still be dull or flat wrong. A precise technical passage might score "difficult" just because the subject needs longer words. The syllable count is an estimate too, so proper nouns and coined words can be off by one. Treat the consensus grade as a strong signal, not a verdict, then read the thing out loud and trust your ear.
Frequently asked questions
If someone asks me for one readability number, which do I give them?
Give them the consensus grade, since it averages the five grade formulas and cancels out the quirks of any single method. The exception is when a specific standard is required. Healthcare projects often ask for SMOG by name, and anything reviewed in Microsoft Word gets measured on Flesch-Kincaid, so quote the one the reader expects.
Why does the consensus grade leave Flesch Reading Ease out?
Because Reading Ease reports how easy the text is to read rather than which school grade can read it. Averaging it with five grade numbers would mix two different units, and the result would be meaningless. So the consensus uses only the five formulas that report a U.S. grade, and Reading Ease sits beside it as its own reading.
How much text do I need before the scores settle down?
More than a sentence or two. SMOG was designed around a 30-sentence sample, and all of these formulas get jumpy on short text, where one runaway sentence swings the whole average. A full paragraph is the floor, a few hundred words better. Short snippets are fine for a rough check, just do not treat them as precise.
Do headings, bullet points, and line breaks change my score?
They do, and it is worth knowing why. A line break counts as the end of a sentence here, the same as a period, because a heading or a bullet is a unit of reading whether or not anybody punctuated it. So four bullets score as four short sentences, not as one twelve word run-on. That matters most for button labels, error messages and anything else written in fragments, which read far harder than they are if the line breaks are ignored. Rewriting a long sentence still moves the number more than any amount of layout, so treat the two as separate jobs, just not as unrelated ones.
Can I hit a target grade just by chopping sentences?
Partly. Shortening sentences lowers the length-driven scores fast, so Flesch-Kincaid and ARI will drop quickly. But Fog and SMOG hang on your long words, so if your vocabulary stays heavy those two will lag behind and hold the consensus up. When one score refuses to fall while the others do, that gap is pointing at your word choice, not your sentence length.
What counts as a sentence or a syllable in this tool?
A sentence ends at a period, question mark, or exclamation point, or at a line break. A word is a run of letters or digits, with an apostrophe or hyphen inside it keeping it whole, so "don't" and "state-of-the-art" each count once and so does a figure like 1,500. A syllable is estimated by counting vowel groups and dropping a silent final "e," which is fast and accurate for ordinary writing. The honest edge cases: an abbreviation like "e.g." can read as a sentence break, and an odd spelling can miscount by a syllable. A figure counts as a word but is left out of the syllable average, because there is no way to know from the page whether you would read 1984 as four beats or as nine, and guessing would drag the average down on anything full of numbers. That is why the character-based scores are worth a look, since they do not lean on the syllable guess.
Does this work on text that is not in English?
No, and the tool now says so instead of scoring it anyway. All six formulas count English syllables or English letters, so a paste in Russian, Greek, Arabic, Hebrew, Thai, Chinese, Japanese, or Korean gives them nothing to measure. When fewer than half the words use the Latin alphabet the page shows the word and sentence counts and withholds the six scores. Before that check existed a Russian paragraph came back as "very easy, roughly 5th grade" on a reading ease of 199.7, which is a number the formula cannot actually produce.
Is my text private, and does it work offline?
Yes to both. Everything is calculated in your browser, so nothing you paste is sent anywhere, stored, or tracked. Score an unpublished draft or a confidential document without a second thought. Once the page has loaded it keeps working with no connection at all.