Keyword Density in SEO

What is Keyword Density?

Keyword density is a metric used in search engine optimization (SEO) to measure the frequency of a particular keyword or keyphrase within a webpage's content, expressed as a percentage of the total word count. It is a way to assess how often a specific keyword appears in relation to the overall content on a webpage.

For example, "keyword mapping" appears 23 times on the keyword mapping page, which has 1,322 words of content, making the keyword density for that phrase 1.74%.

Why was Keyword Density Important?

Keyword density was once considered important in SEO for several reasons, but its significance has diminished over time. Keyword density was once considered important because search engines, especially in their earlier iterations, used keyword density as one of the signals to determine the relevance of a webpage to a specific search query. Pages with a higher keyword density were thought to be more relevant to the query. 

However, as algorithms developed and AI started being used, more effective ways to determine relevance started being used.

The idea in the past was that by optimizing a webpage's keyword density for specific keywords or phrases, you could increase the likelihood of that page ranking higher in search engine results for those terms. Higher rankings could lead to more organic traffic. This is not the case anymore, but many beginners or non-experts may still falsely believe keyword density is important.

How Do You Calculate Keyword Density?

To calculate keyword density, you can follow these steps:

  1. 1
    Choose a Target Keyword or Keyphrase: Start by selecting the keyword or keyphrase you want to calculate the density for. This should be a relevant term related to the content on your webpage.
  2. 2
    Count the Number of Times the Keyword Appears: Read through the content on your webpage and count how many times the target keyword or keyphrase appears. This includes both exact matches and variations (e.g., plurals, synonyms) if they are relevant.
  3. 3
    Determine the Total Word Count: Calculate the total number of words in your content. You can do this manually by counting each word, or you can use online tools or word processing software that provides word counts.
  4. 4
    Apply the Formula: Use the following formula to calculate keyword density:
    Keyword Density = (Number of times keyword appears / Total word count) x 100
    For example, if your webpage has 500 words and your target keyword appears 15 times in the content, the keyword density would be:
    Keyword Density = (15 / 500) x 100 = 3%
  5. 5
    Express Keyword Density as a Percentage: The result will be a percentage that represents the keyword density for your target keyword in the content.

What is TF-IDF?

TF-IDF stands for "Term Frequency-Inverse Document Frequency," and it is a numerical statistic used in information retrieval and text mining to measure the importance or relevance of a term within a web page relative to a collection of web pages. TF-IDF is a technique that helps identify the most significant words or terms in a web page or set of web pages based on their frequency and importance.

Here's a breakdown of how TF-IDF works:

Term Frequency (TF)

This component measures how often a term appears on a web page. It is calculated as the ratio of the number of times a term appears in a document to the total number of terms in that document. The idea is that terms that appear frequently in a document are likely to be important for understanding the content of that document.

TF = (Number of times the term appears in the document) / (Total number of terms in the document)

Inverse Document Frequency (IDF)

This component measures the importance of a term across a collection of web pages. It is calculated as the logarithm of the ratio of the total number of web pages on the site to the number of pages containing the term. The IDF value increases for terms that are rare across the entire corpus but are present in only a few documents. This reflects the idea that rare terms can be more informative or discriminating.

IDF = log((Total number of documents in the corpus) / (Number of documents containing the term))

TF-IDF: To calculate the TF-IDF score for a term in a document, you simply multiply the TF and IDF values:


The resulting TF-IDF score is a measure of the importance of a term within a specific web page relative to its importance across the entire website. 

Higher TF-IDF scores indicate that a term is both frequent within the web page and relatively rare across the website, making it more likely to be a meaningful and significant term for that page.

What’s the Best Keyword Density for SEO?

There is no specific "best" keyword density for SEO that applies universally to all types of content and websites. Keyword density, as a standalone metric, has become less and less important in modern SEO. Instead, the focus has shifted toward creating high-quality, user-focused content that provides value to your audience and focuses on specific topics. Search engines like Google have evolved to consider a wide range of factors beyond keyword density when determining a page's relevance and ranking.

What Is Keyword Stuffing?

If a keyword has been noticeably used too often, or artificially inserted into a piece of content in order to appear more relevant, then that is considered keyword stuffing. This is a practice that should be avoided at all costs as search engines like Google could penalize your page or website for doing this.

After all, Google’s ultimate goal is to make sure its users find highly valuable, relevant, and unique content, and keyword stuffing goes against this because it doesn’t add any value to the reader. Instead, it creates a poor reading experience that is immediately noticeable.

How Many Keywords Should Be Used in My Content?

There’s no set rule for this, but when writing an article that focuses on a specific topic, you will naturally have a primary keyword that is the most relevant to your topic, along with secondary keywords that support and expand upon that primary keyword.

As long as they are used naturally within the copy and not forced, then it doesn’t really matter how many keywords have been used.

Should I Use Keyword Variations?

Variations of your primary and secondary keywords should come naturally when writing an original content piece. If in doubt, do some more keyword research to see what terms, phrases, and questions your audience is searching for, so you can use the most relevant keyword variations within your page.

Keyword Density Best Practices

Here are a few top-level guidelines when it comes to keyword density, as you create your web content:

Never Aim for a Set Keyword Density

As mentioned previously, keyword density is an outdated method for measuring relevancy, so there’s no set keyword density that is better than the other. The key is to stay true and focused on the article's topic.

Concentrate on Topic Coverage & Depth Instead

Instead of looking at keyword density, focus on how much of your topic you’ve covered within your content piece and how in-depth you’ve covered it. It’s been shown through studies that longer-form content which has the opportunity to cover a topic in much more depth than shorter pieces, tends to acquire more backlinks and do better in search engine rankings.

Include Keywords in the Main Areas

Ultimately, we’re not saying to avoid using keywords within your content, but make sure they are at least in the following key areas: The page title (even if it’s not exact), the meta description, the H1 heading, and the page URL. This way, it will be easy for the reader to determine the relevance of the page within the SERPs.

Hike + Keyword Density

Because keyword density isn’t used anymore, Hike doesn’t measure it, however, in the Content Wizard tool, which uses Chat-GPT4 to write article drafts, the user is able to add relevant keywords that will be naturally sprinkled throughout the content.

If you haven’t yet tried Hike, sign up today and see how easy it is to become empowered to take control of your SEO.