Keyword frequency is more what you need

Keyword frequency is the number of keywords in the content, regardless of how long that content or the keyword is. For example, if the keyword ‘gold watch sale’ was in a 100-word piece of content three times, the keyword frequency would be three. If it was in a 200-word piece of content, it would still be three.

Using keyword frequency as a measurement is less accurate than keyword density, but it’s a much easier measure for site owners to follow. Most search engine optimisation experts recommend a keyword frequency of two or three every 250 words.

It would be a wonderful world if some clever SEO expert could figure out the perfect keyword density and every site owner could apply it. Unfortunately, it’s not going to happen. This is first of all because the search engines protect their optimum keyword density figures vigorously, and no-one could blame them. However, even if an SEO genius stumbled upon the scene that could reverse-engineer the search engine algorithms to produce an exact density, it still wouldn’t work. Most people aren’t going to sit down and figure out the percentages of keywords in their content. Keyword frequency is a much more friendly approach.