What Is the Readability Checker?
The Readability Checker is an online readability calculator that tells you how easy or hard it is to understand a piece of writing. It gives you three important pieces of information:
- Reading level: The grade level the writing is best suited for
- Readability score: The readability level for the selected scale or score
- Note: A quick summary of what the level means
How to Measure Readability Scores
- Make sure your text is spell-checked and properly punctuated. Well-formatted and grammatically correct text will get the best results.
- Type or paste your text into the box or click the upload icon in the top right corner to upload a text or Word file.
- Choose the scale or score. By default, the tool shows the Flesch-Kincaid reading score, which is a common measure of text readability.
- The readability score, reading level, and reading note will be displayed instantly. You can also see the word count and character count under the text box.
How Do Readability Formulas Work?
Different readability formulas use different factors to calculate how easy a text is to understand. Some typical factors are sentence length, word length, the words themselves, and the number of words, sentences, and / or syllables.
Each readability formula works best for a particular type of content. Some formulas are tuned for healthcare and legal documents, while others are better for general non-fiction and educational content.
On this web page, you can check readability scores using popular scoring methods: Flesch-Kincaid, Gunning Fog Index, SMOG Index, the Automated Readability Index (ARI), and the Dale-Chall Readability Formula.
Flesch-Kincaid
The Flesch-Kincaid formula measures readability by analyzing sentence length and syllable count. Shorter sentences and words with fewer syllables make a text easier to read. The Flesch-Kincaid Grade Level also shows which US school grade level is required to understand the text.
Ideal Flesch-Kincaid score: A common guideline is a score of 60-70 (grade 8-9 or lower) for text that will be easily understood by most adult English readers.
Gunning Fog Index
The Gunning Fog Index calculates readability based on sentence length and sentence structure, and particularly average sentence length. It also takes into account the number of difficult words, defined as words with three or more syllables.
Fewer difficult words and shorter average sentence length result in a lower Gunning-Fog score, meaning the text is easier to read. This method was originally designed to reduce unnecessary complexity in business writing.
Ideal Gunning Fog score: For a general audience, guidelines recommend a score under 12, or preferably 7-8 for maximum readability.
SMOG Index
SMOG (Simple Measure of Gobbledygook) counts polysyllabic words (those with three or more syllables) to determine readability. It's particularly useful for healthcare and legal documents that use complex language.
Ideal SMOG Index score: Guidelines suggest grade 5-6 for widely distributed informational material and grade 7-8 for general good readability.
Automated Readability Index
The Automated Readability Index (ARI) uses the number of characters per word rather than syllables. This makes the ARI unique and more suitable for technical writing. It was originally developed for military applications but remains popular today.
Ideal ARI score: A grade level of 7-9 matches the reading level of the general US population.
Dale-Chall
The Dale-Chall formula works by using a list of words that most 4th-grade students understand. This makes it particularly good for ensuring that content is accessible to younger readers. If your text uses many words that aren't on this list, it's considered harder to read.
Ideal Dale-Chall score: A score of 4.9 or lower means the text is readable by students in US grade 4 or lower. 6.0-6.9 represents the average US adult reading level.
Are Readability Scores Reliable?
While readability scores are useful, they should be used in conjunction with other methods to evaluate text clarity. This is because most readability formulas and graphs only consider two things:
- Sentence structure, typically measuring the average number of words or characters per sentence
- Word structure, which is usually the average number of syllables per word or the proportion of easy words, determined by referencing a word list
As a result, scores often ignore factors like syntax, tone, style, and vocabulary range, which are important if you aim to write well for a particular audience.
Different readability formulas may also produce different grade levels for the same text, which means an average of several scores can be more useful.
Related Tools
- Character Counter: Count the number of characters, words, paragraphs, and sentences in a text.
- Word Counter: Count the number of words and unique words in a text.