Free Tool
Readability Score Calculator
Hard text loses readers before the argument lands. This calculator scores pasted text for reading ease — and checks the headings and the keyword density while it is here.
Runs entirely in your browser. Nothing you type leaves your device, and nothing is stored or sent anywhere. The output is a planning aid built from the figures you enter — check the results before relying on them.
What this tool does
Paste your article text and the calculator returns the Flesch Reading Ease score and the grade level, with the word, sentence and syllable counts behind them. The formula is public and the counting is local: nothing you paste leaves your device, and the score is a readability measure, never a ranking prediction.
Two more checks share the page because they belong to the same editing pass. The heading mode counts the headings, flags skipped levels and missing or duplicate top headings. The density mode counts a term’s occurrences and its share of the words — and states plainly that keyword density is not a ranking factor, so the check is for stuffing, not for optimisation.
Try it
Waiting. Paste your text, or switch to the heading or density check, then press Calculate.
How it works
Flesch Reading Ease is 206.835 minus 1.015 times the average words per sentence, minus 84.6 times the average syllables per word. The grade level is 0.39 times words per sentence plus 11.8 times syllables per word, minus 15.59. Syllables are counted by vowel groups in each word, with a silent final e removed — a heuristic, not a dictionary, and long words are where it is least exact.
The heading check reads H1–H6 tags or Markdown # markers, one per line, and flags a missing or duplicate H1 and any jump of more than one level. The density check counts the term’s occurrences as a substring and divides by the word count.
Assumptions and limitations
Readability scores measure the text, not the reader.
- Syllable counting is a heuristic. It is accurate enough for a readability score and wrong on some individual words — the score is a guide, not a measurement.
- Flesch measures sentence length and word length. It does not measure clarity, accuracy, structure or whether the article answers the question.
- Keyword density is not a ranking factor. Google has said so for years: the density check exists to catch stuffing, and a “good” density is not something to aim for.
- Heading checks read one heading per line. Paste the headings themselves, not the whole article, or the non-heading lines will be flagged as skipped.
Worked example
Example (illustrative inputs, not a published article). A short passage of plain sentences:
| Item | Figure |
|---|---|
| Words / sentences | 56 words, 10 sentences |
| Flesch Reading Ease | About 85 — Easy |
| Grade level | About grade 3 |
| Heading check on the example | 5 headings, 1 H1, no skipped levels |
Frequently asked questions
What is a good Flesch score?
For general readers, 60–70 is standard and 70–80 is fairly easy. A beginner guide should aim higher than a technical reference — the audience decides, not the number. A score of 90 on a complex subject usually means the content was cut, not clarified.
Does a higher readability score help me rank?
Not directly. Readability helps readers finish the article, and finished articles earn the links and return visits that do help. The score is a reader measure, never a ranking factor.
Why does the heading check flag skipped levels?
Because a jump from H2 to H4 breaks the outline — for readers and for assistive technology. Headings are a hierarchy, not a styling choice; if a section needs a bigger look, change the style, not the level.
What density should I aim for?
None. Keyword density is not a ranking factor, so there is no target to hit. Use the term where the reader needs it and stop counting. The check is here to catch stuffing, not to set a goal.