Improved search engine ranking is possible as you tweak the keyword density of your web pages. This article explores what keyword density is and how to use it to improve your rankings.

What is keyword density?

Keyword density refers to the number of times a keyword combination occurs in a document divided by the total number of words in the document. Keyword density is usually expressed in percentage points. A percentage point of 2% would mean that for every 100 words in a document, that keyword combination occurs twice.

The simplest kind of search engine to build would be one that looks for a particular keyword combination and counts the number of times it occurs in a document. The one with the most occurrences would rank first on down to the document that mentions the keyword only once. The problem with this approach is that it wouldn't take people long to game the search engine by simply repeating their targeted keyword over and over again. The one with the most occurrences wins. Any modern search engine today rejects that method of ranking. In fact, most times, that kind of behaviour will get you banned from the search engines.

What about multiple word keywords?

When you have a keyword that is three words long, you would take the total number of words in a document, divide the total by three for the three words. This gives you the number of words to compare occurrences against. You then divide the number of occurrences of the keyword by the number of words you just calculated. This will give you your keyword density for this keyword combination.

Why does keyword density matter anyway?

Keyword density speaks to the readability of a document along with its potential relevance to a particular keyword combination. In theory, certain percentage levels represent a naturally written document while other percentage points suggest someone trying to trick the search engines to give them a higher search engine ranking than they deserve. The density of your keywords is one of hundreds of metrics modern search engines use to rank your pages. I could fill pages and pages on all the metrics search engines are know to use or are suspected of using. Keyword density is one of many items that you should be thinking about when creating web pages full of content.

How can you tell what your keyword density is?

It won't take you long to figure out that checking keyword density by hand is quite a chore. It is a task well suited to a computer though. A site I use to check keyword density can be found at http://www.ranks.nl/tools/spider.html

What kind of density percentage should I focus on?

Different search engines prefer different density percentages. Yahoo seems to prefer something around the 4% mark while Google prefers something around the 2% mark. MSN seems to prefer a density that is higher than both Google and Yahoo. As long as you remember that the having the right percentage doesn't guarantee high ranking and that you need to do a whole lot of little things right, you'll be in the right path to improved search engine ranking.