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What is Keyword Density?

Keyword Density Explained

It is vital to understand the importance of what keyword density is and how keyword density works, since it can have a direct impact on your site's content visibility in search engine results pages. Keyword density is the number of times your main or focus keyword is used in your content in comparison to the total text of that page. For example if you had a 1,000 word page at least 20 of those words should be your main term you are wanting to rank for.

Why is Keyword Density Important for SEO?

Your keyword density is important for SEO because Google tries to match a user’s search query to the best fitting web pages. To do this Google needs to understand what your web page is about. This is why it is important to use your keyword which you’d like to rank for throughout your content. If you’d like to rank for, for instance ‘Boiler Installations London’ you probably use this phrase regularly throughout your text.

If you repeat your keyword very often in your content it becomes spammy and unpleasant to read for your visitors, this is something you should avoid at all times. After all, you want users to enjoy and understand your content, a high keyword density is also a signal to Google that you might be stuffing keywords in your text – also known as over-optimising. As Google likes to show the best result to users, both in relevance and readability, this can negatively affect your rankings.

Keyword Density Formula

Keyword density can be calculated as a specific figure, should you need to. To determine the keyword density of a webpage, simply divide the number of times your focus keyword is mentioned by the total number of words on the page, the resulting figure is the keyword density of the page.

What is TF-IDF?

A more advanced way of measuring keywords density is <i>Term Frequency and Inverse Document Frequency</i> or TF-IDF for short. This formula helps to determine how important a given term is to a document or page. There are a number of variations of TF-IDF that may be used by search engines in some circumstances to quantify the relevance of a page's content to a user's search query, but as always, many other SEO factors come into play.

There is, of course, a FORMULA to work out the local keyword density of any page:

  • Density = ( Nkr / ( Tkn -( Nkr x ( Nwp-1 ) ) ) ) x 100
  • Density = your keyword density
  • Nkr = how many times you repeated a specific key-phrase
  • Nwp = number of words in your key-phrase
  • Tkn = total words in the analysed text

The keyword density score for a key-phrase is calculated by looking at:

  • how many times a specific key-phrase is repeated in a document
  • the number of words in that key-phrase
  • the total number of words in the analysed text.

In Conclusion

When applying keyword density to your text it’s important to keep your focus keyword throughout the whole text, while not over doing it - spamming your text with your focus keyword is frowned upon by Google and could negatively impact your rankings.

However if your keyword density is too low, add your focus keyword throughout your text more often. It is also important to check that your text stays on topic, as it should be easy to mention your keyword enough. If your score is too high, re-read and assess your text first and see if there is any way you can replace your keyword with a synonym.