Domain Authority is a search engine optimization metric that attempts to determine the likelihood, on a scale from 0 to 100, of a website ranking high in SERPs (search engine results pages) based on a domain’s backlink profile. The name was coined by Moz and derived from Google’s PageRank. Other companies, such as aHrefs and Majestic, maintain their own iteration with different algorithms and names.
How is Domain Authority calculated?
Moz defines how their Domain Authority is calculated as:
Domain Authority is calculated by evaluating linking root domains, number of total links, MozRank, MozTrust, etc. into a single DA score. This score can then be used when comparing websites or tracking the “ranking strength” of a website over time.
This breaks down to Moz indexing millions of websites and analyzing how each site links to one another. The total number of domains linking to your site as well as the total number of links to your websites, the higher the score. Moz goes a couple steps further and adjusts a website’s score based on the score of the websites that link to your website. So, if your website had one link from a domain that had a Domain Authority of 80, your domains score would be higher in comparison to having five links from websites with a Domain Authority of ten.
In addition to the strength and quantity of backlinks to your domain name, Domain Authority is based on a logarithmic scale. This means that it’s easier to achieve increase your Domain Authority by five points if your original domain authority is a fifteen as opposed to a domain that has a rating of sixty.
How often is Domain Authority updated?
As of this writing, Domain Authority is updated, on average, once a month. I have seen updates as early as once every couple of weeks and as long as 45 days. Subscribers to one of the Moz Pro plans are given a date of the current ranking and when the next ranking change is estimated to become available.
What is the difference between Domain Authority, Domain Rating, and PageRank
Domain Authority is what Moz issues as a domain ranking metric. aHrefs issues their ranking as “Domain Rating”. PageRank was the original. If was the ranking issued by Google and is no longer updated. The name “PageRank” was named after the founder of Google, Larry Page, and is defined by Google as:
PageRank works by counting the number and quality of links to a page to determine a rough estimate of how important the website is. The underlying assumption is that more important websites are likely to receive more links from other websites.
What Domain Authority is not.
Whether using Moz’s Domain Authority or aHref’s Domain Rating, these metrics are important to watch to get an overall idea of the health of a domain. It is not, by any means, the only KPI or metric that someone should use judge the success of their website in regards to search engine optimization. I have personally outranked many websites who’s ranking was over double the ranking of my clients. Also, be aware that both Domain Authority and Domain Rank will fluctuate as the algorithms are changed.
So, again, this is a great metric to watch but don’t put all of your attention towards it. A business owner should have a broad overview of the health of their website’s organic ranking. Instead of just looking at one metric, you should include Domain Authority in with a variety of metrics that include organic traffic, total high-quality backlinks, target keyword ranking, leads, and sales. When taking on a search engine optimization campaign, you and your SEO should plan out what metrics are most important for your business and industry.