Count the number of words in the document. If the document is on a computer, you can use a word counter within the word processing software, download software or copy and paste the text to a website with the ability to determine word count.
Count the number of times the specific word you are analyzing appears in the document.
Divide the number of occurrences by the number of words in the document. For example, "word" occurs 14 times in this 212-word article. So, 14 divided by 212 equals .066
Move the decimal over two spaces, or multiply by 100, to determine the percent. In this example, .066 becomes 6.6 percent.