What is keyword density and what is the formula for knowing?

[daica85]

Keyword density tells you how often a search term appears in a text in relation to the total number of words it contains. For example: if a keyword appears three times in a 100 word text the keyword density would be 3%. From the point of view of search engines, a high keyword density is a good indicator of search engine spam. If a keyword appears too often in a website, search engines will downgrade the website and it will then appear lower down in search results.

There's no magic formula of how many keyword in the content (as know as keyword density), however the acceptable percent is around from 0,5% to 3%, that's good for SEO content.