Keyword density is the percentage of how often a specific word or phrase appears in a piece of content compared to the total word count. It’s key for SEO, helping search engines see how relevant your page is for certain searches. To calculate it, just divide the number of times your keyword shows up by the total words and multiply by 100. While aiming for around 1% to 3% can help with visibility, focusing on creating engaging and valuable content should always come first.