Keyword Density calculation formula and checking tool

http://www.seocentro.com/tools/seo/keyword-density.html

http://tools.seobook.com/general/keyword-density/

http://www.webconfs.com/keyword-density-checker.php

http://www.seomastering.com/keyword-density-analyzer.php

Divide the number of times the keyword was used with the number of words in your article. Once you discover the answer, multiply this number by 100 (Example: 40 / 1000 = 0.04 * 100 = 4%).