When you're evaluating keyword density, you need to decide on your keyword phrase and then write your page. Once you've chosen a keyword phrase for your Web page, you need to start using it. As you probably already know, you should use your keyword phrase in:
- the meta title
- meta keywords
- meta description
- h1, h2, and h3 headlines (and h4-h6, if you have them)
- the first paragraph of text in the HTML
- in link text
- in alternate text for images
- scattered throughout the rest of the text on the page
But if there isn't a lot of text on the page, repeating your keyword phrase that many times could end up with a page that is too keyword heavy. In other words, your keyword density is too high.
Your First Rule Must Be Readability Not Keyword Density
And not readability by search engines, but by your customers. If your customers find the text annoying to read they won't be your customers very long, no matter how dense or sparsely you've repeated your keyword phrase. So the first thing I do, especially if I think I've written a page that is too keyword dense is have someone else read the article. Once they're done I'll ask them to sum up what they thought the article was about in 2 or 3 words. I also ask them about the writing - did they find it repetitive? Most of the time, if your test audience doesn't mind the repetitions of your keyword phrase, then you probably haven't included it too often.
Strive for a Keyword Density of No More than 5%
This means that out of the entire Web page content, your keyword phrase should be no more than 5% of the total words. If it is more than that, you risk appearing like a keyword spammer to search engines or annoying your customers with hard-to-read pages.
I aim for a keyword density of 3-4% for my target phrases. I've found that this works to get the keyword phrase into the mind of my reader without screaming at them "I'm targeting ________ as my keyword phrase". I've found that if I ask my test readers what they think the keyword phrase is, if they can get it right away, it's probably too dense. But if they can come close without being 100% I'm hitting the mark.