What is Keyword Density???

no. of keyword appeared in a content out of total no. of words. keyword density should be 2 to 3%

Every page have some word. keyword density calculation is not so complex method. Total No of the word in the pages divided by NO keyword in the pages then then multiplied by hundred.

Keyword Density = (No of keyword/ No of word in pages)*100

It is a throw back to the early days of SEO when keyword stuffing worked. All that you need is for your primary keyword phrase to appear in the Page Title, the Page description, and in the content once and you will do well!

Must admit until very recently I was still convinced you still had to worry about keyword density, prob because just about every SEO tool going still mentions it, but I've seen the error of my ways.

As Eosplaces says, don't worry about it!

Keyword Density is the ratio, how many time you will use a keyword in your content. It is standard 4%-5% means if your web content is 100 then, you will use your keyword maximum four to five time because more then use comes in Black hat SEO technique "Keyword Stuffing" and search engines are not allowed it.
There are many tools to check the density of your keywords.
I use
quickregister.net/seotools
It provides many important SEO tools for use freely.

So you still believe in Keyword Density taniasharma?

Assuming you mean in your content. Just add your keywords in about 3 times.

PageRank wise, don't worry about it.