What is readability?

Readability is all about how easy or difficult it is to read something.  

Readability depends on a text’s presentation (e.g. font choice, spacing, colours, etc.) and context (i.e. the actual words and sentences that are written on the page).

Other factors go into a text’s readability, like sentence length, sentence structure, and the average syllables per word. These combined factors help assess whether your writing is likely to be understood and avoid writing mistakes that lead to confusion. 

Readability matters. Checking your writing for readability can help you communicate your message in a way that’s clear and easy to understand for the reader. We recommend you aim for a reading age of between age 9 and 15.

Why should I care about readability?

Many people are surprised to learn that over 40% of Australians have literacy levels below what is considered enough to get by in everyday life.

And most people don't realise that at least one in ten visitors to a website will be dyslexic or that many more than that will have cognitive difficulties or a learning disability.

People also do not read one word at a time. They bounce around - especially online. They anticipate words and fill them in. When you write more, people understand less.

How do I measure readability?

The Flesch reading ease test measures the readability of a text. It uses two variables to determine the readability score:

  • the average length of your sentences (measured by the number of words)
  • the average number of syllables per word

Then, it gives you a score between 0 and 100. A score of 100 means your copy is very easy to read. And, a score of 0 means your text is very difficult to read.  You can see the exact interpretation of all the scores on the scale in the table below. This is another reason why we recommend a reading age of between 9 and 15 years old.




Very easy to read, easily understood by an average 11-year-old student


Easy to read


Fairly easy to read


Easily understood by 13- to 15-year-old students


Fairly difficult to read


Difficult to read, best understood by college graduates


Very difficult to read, best understood by university graduate

9 top tips for better readability

  1. Use plain English
  2. Nobody’s got time for jargon and unnecessary buzzwords
  3. Get straight to the point. Cut dead wood and waffle
  4. Cut repetitive words
  5. Use bullet point or numbered lists
  6. Address your readers directly - ‘you’ and ‘we’
  7. Make it easy to read - use white space and clear sub headings
  8. Define any acronyms or abbreviations
  9. Keep it short

How long should a sentence be?

25 words is our absolute limit. 

Studies also show that sentences of 11 words are considered easy to read, while those of 21 words are fairly difficult. At 25 words, sentences become difficult, and 29 words or longer, very difficult.

If you write short sentences using plain English, it’ll help more people understand your content.

Long, complicated sentences force users to slow down and work harder to understand what they’re reading. This isn’t something people want to do, even if they’re familiar with the subject or language you’re using.

Our rule of thumb is: If it’s complex, make it simple

How Texthelp can help you master readability

The ReachDeck Editor guides you to create content in line with accessibility best practice. 

It’s a grammar, spelling and readability checker that helps everyone in your organisation to create internal and external content that’s easy to understand.

With ReachDeck, you can: 

  • Highlight grammar, spelling and readability errors as you write
  • Write in plain English, identifying reading age, long sentences and jargon words