Keyword Density: Formula, Examples and Limitations

01

What Is Keyword Density?

Keyword density is the frequency of a word or phrase expressed relative to the total length of a text. A raw count tells you that a keyword appears 8 times. Density adds the denominator: 8 occurrences in 400 words is more concentrated than 8 occurrences in 2,000 words.

The metric is descriptive. It tells you what is present in the text, not whether the content is useful or whether a search engine will rank it. The same percentage can sound natural in a technical specification and repetitive in a short introduction.

02

The Keyword Density Formula

An occurrence-based calculation divides the number of exact keyword matches by the total number of words, then multiplies by 100.

A normalized per-1,000 rate uses the same values:

Before calculating, define how words are tokenized, whether case is ignored, and whether the denominator includes stop words. A repeatable comparison requires the same rules for every text.

03

Keyword Density Example

Suppose “content analysis” appears 6 times in a 1,200-word article. Under the occurrence-based formula, its density is 6 ÷ 1,200 × 100 = 0.5%. The normalized rate is 5 occurrences per 1,000 words.

Article A has more raw occurrences, while Article B is more concentrated. Neither result says which article is better. That requires reading the pages and evaluating whether the phrase fits their purpose.

04

How Should Phrase Density Be Calculated?

Tools use more than one convention. An occurrence-based method counts the exact phrase once each time it appears and divides by total words. Another method multiplies the occurrence count by the number of words in the phrase before dividing.

Neither convention is useful if the tool hides its formula. This site uses occurrence-based density for unigrams, bigrams, trigrams, and longer tracked phrases. It also reports raw counts, so the result can be recalculated under another convention if needed.

05

Is There an Ideal Keyword Density for SEO?

There is no universal percentage that makes a page rank. Google’s documentation does not prescribe a target density. Its SEO Starter Guide recommends useful, naturally written content and warns that excessive repetition is tiring for users. Google’s spam policies define keyword stuffing as filling a page with keywords or numbers in an attempt to manipulate rankings.

A low density does not prove a topic is missing: a page may use related terminology, entities, examples, or pronouns. A high density does not prove optimization: repetition may come from navigation, product grids, templates, or awkward copy.

06

A Practical Keyword-Density Workflow

When comparing with another page, do not treat its numbers as a recipe. Different intent, brand language, page type, and information architecture can justify a different vocabulary profile.

07

What Keyword Density Cannot Tell You

• Whether the page satisfies search intent
• Whether claims are accurate and sourced
• Whether synonyms cover the topic well
• Whether readers understand the copy
• Whether links and page structure are useful
• Whether Google will index or rank the page

Density is most useful as one transparent diagnostic among several. Pair it with editorial review, factual verification, structure, originality, and user feedback. For a simple vocabulary table, use the word frequency counter. For exact 1–3-word phrases and A/B changes, use the keyword density checker.