Use a readability tool to prioritise content
It cannot tell you how easy your content is to understand. But it can show if the language might be too complex for many people.
Use the SMOG calculator
We use a tool called the SMOG calculator to measure readability.
This uses the number of sentences and complex words (3 or more syllables) to give a readability score.
Before using the SMOG calculator:
- add full stops to the end of every heading and bullet point
- if the title of the content includes a word with 3 or more syllables (for example, “paracetamol"), remove this word from the text
This will help you get more accurate scores when comparing content.
Prioritise content with a score over 14
The lower the score, the fewer complex words you're using.
A score higher than 14 means most users might struggle with the language in your content.
|SMOG readability score||UK adults at this level||Typical literacy skills at this level|
|7 to 9||93%||understands short, simple content on familiar topics from familiar sources|
|10 to 11||76%||understands short, simple content from a range of everyday sources (like newspapers)|
|12 to 13||51%||understands simple content of varying lengths on a variety of topics|
|14 to 16||22%||understands content of varying complexity, from a range of sources|
|17 or more||Less than 22%||able to obtain, interpret and evaluate complex content|
Read our page about health literacy to see why it’s important to create content that’s simple to read.
Do not rely on readability scores alone
A readability score under 14 does not prove your content is useful for your users. It just means you're not using lots of complex words.
Readability scores do not tell you if your content is easy to understand or act on.
You can only find out how well your content works by testing it with users.
Improve your content
When you’ve identified content with a high readability score, look to improve it using:
Updated: July 2019