Readability Score Calculator

For general web content, aim for Flesch Reading Ease 60-70 (standard, 8th-9th grade) and Gunning Fog <= 8. Technical writing can score higher.

Flesch Reading Ease is the most popular. Flesch-Kincaid, Gunning Fog, and SMOG give US grade levels. Coleman-Liau and ARI use character counts instead of syllables — more reliable when syllable detection is uncertain.

Yes. All analysis happens client-side. Your text is never sent to any server.

Yes, the Readability Score Calculator is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.

Absolutely. The Readability Score Calculator processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the Readability Score Calculator is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Readability Score Calculator in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Yes, the Readability Score Calculator handles text of any length with fast, real-time processing. Since everything runs in your browser, performance depends on your device but works well for most use cases.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Readability Score Calculator works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

Flesch Reading Ease comes from two inputs: average sentence length (words per sentence) and average word length (syllables per word). The formula is 206.835 minus 1.015 times words per sentence, minus 84.6 times syllables per word. Because both factors are subtracted, longer sentences and more multi-syllable words push the score down toward 0 (very difficult), while short sentences and simple words push it up toward 100 (very easy). A score of 60-70 is considered standard, roughly 8th-9th grade. Notice that word length carries far more weight than sentence length, so swapping long words for short ones moves the number fastest. This calculator runs the formula on your text instantly and shows the inputs behind it in the Text Stats tab, so paste a draft to see exactly which factor is dragging your score.

Each formula weighs sentence length and word complexity differently and was built for a different purpose, so a one- or two-grade spread between them is normal, not an error. Flesch-Kincaid, Gunning Fog, and SMOG lean on syllable counts and complex words, so syllable-heavy prose scores harder on them. Coleman-Liau and ARI count characters instead of syllables, so they react more to long words spelled with many letters. Gunning Fog and SMOG specifically penalize words of three or more syllables, which makes technical jargon spike their numbers. Rather than trusting any single formula, this tool averages the grade-based scores into one number that smooths out the noise, which is the most stable figure to act on. Paste your text to see all seven side by side and the averaged grade beneath the gauge.

In this calculator, a complex word is any word with three or more syllables, counted by an automated syllable estimator that strips common endings before tallying vowel groups. Words like "information," "opportunity," and "readability" qualify; short words like "house" or "writing" do not. The percentage of complex words is the engine behind several formulas: Gunning Fog multiplies their ratio directly, and the simplified Dale-Chall here uses three-plus-syllable words as a proxy for "difficult" words instead of the original familiar-word list. Because syllable counting is heuristic, an occasional word may be miscounted, but across a paragraph the totals are reliable. The Text Stats tab shows your complex-word count and percentage, so paste your text to spot whether dense vocabulary is what is raising your grade level.

Two mechanical edits move readability scores the most, because nearly every formula penalizes the same things: long sentences and long words. First, split any sentence that runs past 20-25 words into two; shorter sentences cut words-per-sentence, which lifts Flesch Reading Ease and lowers Gunning Fog and ARI together. Second, replace multi-syllable words with plain ones, swapping "utilize" for "use" or "subsequently" for "later," which drops your syllables-per-word and complex-word percentage. Cutting filler clauses and breaking dense paragraphs helps too. The fastest workflow is to paste your draft, note the average grade, simplify the longest sentences and densest words, then recalculate to see the change. Because results update from your own input with no length cap, you get immediate feedback on each edit, so paste your text and start trimming.

Neither type is universally more accurate; they fail in different ways. Syllable-based formulas like Flesch-Kincaid, Gunning Fog, and SMOG capture how hard words are to pronounce, but they depend on syllable counting, which automated tools estimate heuristically and can occasionally miscount on unusual spellings. Character-based formulas like Coleman-Liau and the Automated Readability Index sidestep syllables entirely by using letters or characters per word, so they stay reliable exactly when syllable detection is uncertain. The trade-off is that character counts can misjudge short-but-tricky words. That is why seeing them together is more useful than trusting one: when a syllable-based score looks off, compare it against Coleman-Liau and ARI. This tool calculates all of them at once and averages the grade-based results, so paste your text to compare both approaches on the same passage.