2%-3% per webpage is the ideal keyword density, adding too many keywords will make your webpage look spammy, which is something you do not want.
Keyword density is the percentage of times a keyword or phraseappears on a web page compared to the total number of words on the page. In the context of search engine optimization keyword density can be used as a factor in determining whether a web page is relevant to a specified keyword or keyword phrase.
Yahoo recommends a keyword density of about 3% while Google seems to like sites that have a 1-2% keyword density.
2-3% is the ideal keyword density but you shouldn't start counting the number of times you use a keyword in an article. If your keyword is a part of your headline then odds are you are going to use that keyword several times in your article. Take the example of an article about cat food. How many times will you "cat food" appear in a 500 word article? If you aren't trying to stuff the article with keywords then obviously the most number of times the keyword will appear in your article is 10 times. Or less. Anything more than and it would be overkill.
3 to 4% is the proper keyword density range. if we need we can use upto 6%, but some case it will affect. If you go above 6% it will be a spam.
To rank your site for perticular keywords and phrases, keyword density is important. Also, you should not use too many keywords or Google will consider this as keyword stuffing. Your keyword density should not be more than 2-3% of your total word count.
In common word, Keyword density is percentage of number of times Keyword appeared on a Web page by total number of words in that page. So if in an article of 100 words you are using your Keyword 10 times, your density will be 10%. Many people use different ways and formulas to calculate Key word density .
