Reading Level Converter
MeasurementAnalyse any text to get its Flesch Reading Ease score and Flesch-Kincaid grade level. Paste text or enter a score — free, instant, runs entirely in your browser.
What is a Reading Level?
The Reading Level Converter analyses a block of English text and tells you how easy or difficult it is to read, using two of the most respected and widely adopted readability measures: the Flesch Reading Ease (FRE) score and the Flesch-Kincaid Grade Level (FKGL). Paste any text into the tool, click Analyse, and you immediately see the FRE score on a 0–100 scale, the corresponding US school grade level, a plain-language difficulty label, and a visual FRE bar that shows where the text sits on the ease spectrum.
The Flesch Reading Ease score was developed by linguist Rudolf Flesch in 1948 as part of his research into making government and bureaucratic writing more accessible to ordinary citizens. The formula measures two aspects of a text's structure: how long the average sentence is, and how many syllables the average word contains. Short sentences with short words score near 100 (Very Easy). Long sentences packed with polysyllabic vocabulary score near 0 (Very Confusing). The grade level equivalent — the Flesch-Kincaid Grade Level — was a later refinement developed by Flesch and J. Peter Kincaid for the US Navy in 1975, calibrated so the output maps directly to a US school grade.
The tool also reports three foundational text statistics: total word count, total sentence count, and total syllable count. These are the raw inputs to both formulas and give you an immediate, actionable picture of what is driving your score.
For a focused word count across drafts, pair this tool with the Word Count Calculator. To adjust the case or style of your text before analysing, the Case Converter is a useful first step.
How to use this Reading Level calculator
- Paste your text into the large text area at the top of the tool. The area accepts any plain text — paste from a Word document, Google Doc, email draft, or web page. There is no file upload; copy and paste is the input method.
- Click the Analyse button below the text area. The tool processes the text entirely in your browser — nothing is sent to a server, and any length of text is handled instantly.
- Read the FRE score displayed prominently at the top of the results panel. Check the FRE bar to see visually where the score sits on the 0–100 ease spectrum.
- Note the grade label (e.g. "Grade 8" or "College Level") and the difficulty label (e.g. "Standard" or "Fairly Difficult"). These two outputs together tell you both who can understand the text and how effortful the reading experience is.
- Review the text statistics — word count, sentence count, and syllable count — to understand what is driving the score. If you want to improve the score, a high average sentence length (words ÷ sentences above 20) is the most common lever; reducing it will raise the FRE score meaningfully.
- Edit your text directly (or in your original document), then paste the revised version and click Analyse again to compare. Repeat the cycle until the score hits your target range.
- Share or export the URL — the result state is encoded in the page URL so you can share a specific analysis with a colleague or client.
Formula & Methodology
### The Flesch Reading Ease FormulaFRE = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words)Variable definitions: -words— total number of words in the text -sentences— total number of sentences (delimited by.,!,?, and equivalent punctuation) -syllables— total number of syllables across all words The constant 206.835 is the formula intercept calibrated to English. The coefficient 1.015 penalises long average sentence length. The coefficient 84.6 penalises high average syllables per word. Both penalties reduce the score (making the text appear harder), which is why lower scores mean more difficult text. ### The Flesch-Kincaid Grade Level FormulaFKGL = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59Variable definitions: same as above. The large coefficient on syllables per word (11.8) means that vocabulary complexity has a stronger effect on FKGL than sentence length. A text with very short sentences but many polysyllabic words can still score a high (difficult) grade level. ### How Syllable Counting Works The tool uses a vowel-group heuristic: 1. Convert the word to lowercase and identify all contiguous groups of vowels (a, e, i, o, u). 2. Count the number of distinct vowel groups — this is the initial syllable estimate. 3. Apply correction rules: - If the word ends in a silent 'e' (and the preceding letter is a consonant), subtract one syllable. - If the word ends in 'le' or 'les' and the letter before 'l' is a consonant, add one syllable to account for the syllabic consonant. - Ensure every word has at least one syllable (minimum count is 1). This heuristic produces accurate counts for the large majority of common English words. Rare proper nouns, technical acronyms, and words borrowed from non-English languages may be miscounted. ### Worked Example Sample text: "The cat sat on the mat. It was a warm day." Step 1 — Count words: The / cat / sat / on / the / mat / It / was / a / warm / day = 11 words Step 2 — Count sentences: Two sentences (ending at "mat." and "day.") = 2 sentences Step 3 — Count syllables per word: | Word | Syllables | |---|---| | The | 1 | | cat | 1 | | sat | 1 | | on | 1 | | the | 1 | | mat | 1 | | It | 1 | | was | 1 | | a | 1 | | warm | 1 | | day | 1 | Total syllables = 11 Step 4 — Calculate averages: - Average sentence length = 11 ÷ 2 = 5.5 words per sentence - Average syllables per word = 11 ÷ 11 = 1.0 syllables per word Step 5 — Apply FRE formula:FRE = 206.835 − (1.015 × 5.5) − (84.6 × 1.0) = 206.835 − 5.5825 − 84.6 = 116.65The raw result exceeds 100, which is clamped to 100 — this is expected for very simple text with monosyllabic words and short sentences. The result is classified as Very Easy (Grade 5). Step 6 — Apply FKGL formula:FKGL = (0.39 × 5.5) + (11.8 × 1.0) − 15.59 = 2.145 + 11.8 − 15.59 = −1.645A negative FKGL is clamped to 0, which corresponds to Kindergarten level — again expected for an extremely simple sample sentence. In practice, real-world text of any meaningful length will produce scores within the normal interpretation ranges. For generating sample text to test the tool, the Lorem Ipsum Generator produces placeholder paragraphs you can paste and analyse. To convert and format text before analysis, see the Text to Slug Formatter for URL-safe transformations.
Frequently Asked Questions
The Flesch Reading Ease (FRE) score is a numerical measure of how easy a piece of English text is to read, on a scale from 0 to 100. Higher scores mean easier reading — a score of 90–100 is understood by an average 11-year-old, while a score below 30 is typically understood only by university graduates or professionals. The formula was developed by Rudolf Flesch in 1948 and is still one of the most widely used readability measures in publishing, education, and content strategy.
The Flesch-Kincaid Grade Level (FKGL) translates the readability of a text into a US school grade level. A score of 8.0 means the text is appropriate for an 8th grader (roughly a 13–14-year-old). The formula was developed jointly by Rudolph Flesch and J. Peter Kincaid for the US Navy in 1975 to help assess the readability of technical manuals. Unlike the FRE score, lower FKGL numbers mean easier text — a score of 1–2 is suitable for early readers, while 16+ indicates post-graduate level material.
For general blog content targeting a broad audience, aim for an FRE score between 60 and 70, which corresponds to 8th–9th grade reading level and is considered Standard difficulty. Content marketing research consistently shows that this range maximises both comprehension and engagement across adult readers. Technical blogs or B2B content can go down to 50–59 (Fairly Difficult), but anything below 50 risks losing a significant portion of general readers.
The difficulty labels map FRE score ranges to plain-language descriptions: 90–100 is Very Easy (5th grade reading level), 80–89 is Easy (6th grade), 70–79 is Fairly Easy (7th grade), 60–69 is Standard (8th–9th grade), 50–59 is Fairly Difficult (10th–12th grade), 30–49 is Difficult (College level), and 0–29 is Very Confusing (Professional or Post-Graduate level). These labels were part of Flesch's original 1948 publication and remain the widely cited reference for interpreting the score.
Target 70–80 for consumer-facing web content, landing pages, and marketing copy. For news articles and general interest journalism, 60–70 is standard. Academic writing typically falls in the 30–50 range. Legal and medical documents often score below 30. If you are writing for a specific audience — say, secondary school students — target the FRE score that corresponds to one or two grade levels below the expected reading level of your audience so the content feels accessible rather than effortful.
Readability scores are sensitive to sentence length and syllable count, not to vocabulary difficulty, complexity of ideas, or domain knowledge required. A long, grammatically simple sentence full of short words will score easier than a short sentence containing technical polysyllabic terms. Common reasons for unexpected scores include very long sentences (which raise FKGL dramatically), heavy use of Latin-origin or technical words with many syllables, passive constructions that extend sentence length, and abbreviations that the syllable counter may parse unexpectedly.
The syllable counter uses a vowel-group approach: it counts contiguous groups of vowels (a, e, i, o, u) in each word, then applies correction rules — silent final 'e' is subtracted, words ending in 'le' or 'les' after a consonant get one syllable added, and every word is counted as having at least one syllable. This heuristic gives accurate counts for the vast majority of common English words. Proper nouns, acronyms, and very unusual words may be miscounted, which is expected behaviour for any automated syllable counter.
Paste your draft text into the text area and click Analyse. Review the FRE score against your target range and the grade level against your intended audience. If the score is too low (text is too hard), look at the sentence count and word count outputs — long average sentence length is usually the first culprit. Break long sentences into two, replace polysyllabic words with shorter synonyms, and re-run the analysis. Repeat the cycle until the score hits your target. For word count tracking across multiple drafts, the [Word Count Calculator](/word-count-calculator/) is a useful companion.
Yes. While Google has not officially confirmed readability as a direct ranking factor, readable content correlates strongly with lower bounce rates, higher dwell time, and more social shares — all signals that influence rankings indirectly. Most SEO practitioners recommend targeting an FRE score of 60–70 for informational content aimed at general audiences. Using this tool alongside the [Word Counter Formatter](/word-counter-formatter/) helps you optimise both readability and length for search-intent-aligned content.
The original Flesch formula was designed for English and its constants (206.835, 1.015, and 84.6) are calibrated to average English word and sentence lengths. Adapted versions exist for German, Dutch, French, Spanish, and other languages with different constants, but this tool uses the standard English formula. Applying it to non-English text will produce a score, but the interpretation will not be meaningful because syllable structure and average word length differ significantly across languages.
Both formulas use the same two inputs — average sentence length and average syllables per word — but they weight them differently and produce different outputs. Flesch Reading Ease outputs a score from 0 to 100 where higher is easier. Flesch-Kincaid Grade Level outputs a US school grade number where lower is easier. Practically, they are inverses of each other: a high FRE score corresponds to a low FKGL, and vice versa. For communicating readability to a non-specialist audience (clients, editors, managers), the difficulty label from FRE is usually clearer; for academic or curriculum contexts, FKGL is more directly useful.
Copy text from any source — a Word document, a Google Doc, a web page, an email draft, or a PDF — and paste it directly into the text area on the tool. There is no file upload; only plain text is accepted. Formatting like bold, headers, and hyperlinks is stripped automatically when pasted as plain text. Click the Analyse button and the results appear immediately. For best results, paste at least 100 words — very short samples produce statistically unreliable scores because the averages are based on a tiny number of sentences.
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