Domain Authority

Quick Answer

Domain Authority (DA) and Domain Rating (DR) are third-party metrics created by Moz and Ahrefs respectively. They estimate a website's ranking strength on a 0-100 scale based on its backlink profile. They are useful benchmarks, but they are NOT Google ranking factors. Google has confirmed it does not use any third-party authority score.

What Is Domain Authority?

Domain Authority is a score developed by Moz that predicts how likely a website is to rank in search results. It was introduced in 2010 as an approximation of Google's old PageRank system, which Google stopped making public in 2016 (Moz, 2024).

DA is calculated using machine learning models that analyze a site's link profile, including the number of linking domains, link quality, and link diversity. The score runs from 0 (brand-new site, no links) to 100 (sites like google.com and wikipedia.org).

Ahrefs has a similar metric called Domain Rating (DR). While they measure the same concept, they use different calculations and data sets, so a site's DA and DR scores are often different. For example, a site with DA 45 might have DR 52 because each tool crawls and indexes links differently.

DA vs. PA: Domain vs. Page

These are related but distinct metrics:

Domain Authority (DA) measures the strength of an entire domain (example.com). It reflects the overall link profile of the whole website.
Page Authority (PA) measures the strength of a single page (example.com/specific-article). A high-DA site can have low-PA pages, and vice versa.

When evaluating a backlink opportunity, PA of the linking page matters more than DA of the linking domain. A DR 40 site with a page that has 200 referring domains will pass more equity than a DR 80 site with a page that has zero referring domains (Ahrefs, 2024).

How DA and DR Are Calculated

While the exact formulas are proprietary, here is what each tool considers:

Moz Domain Authority

Total number of linking root domains
Total number of individual backlinks
Quality and spam score of linking domains
Machine learning model trained against actual Google rankings

Moz recalculates DA on a regular crawl cycle. Their web index contains over 44 trillion links across 800 million domains (Moz, 2025).

Ahrefs Domain Rating

Number of unique domains linking to the target
DR values of those linking domains (recursive calculation)
Number of unique domains each linking site links to

DR is a logarithmic scale, meaning going from DR 70 to DR 80 requires exponentially more links than going from DR 20 to DR 30. Ahrefs updates DR daily and their crawler processes over 8 billion pages every 24 hours (Ahrefs, 2025).

Quick Answer

Google does not use Domain Authority, Domain Rating, or any third-party authority metric in its ranking algorithm. Google uses its own internal systems to evaluate page and site quality. DA and DR are useful for comparing sites and tracking progress, but chasing a higher score should never be the goal itself.

Why DA Is NOT a Google Ranking Factor

This is one of the most common misconceptions in SEO. Google's John Mueller has explicitly stated that Google does not use third-party domain authority scores for ranking (Google Search Central, 2024). Here is why the confusion exists:

Correlation is not causation. High-DA sites tend to rank well because they have strong link profiles, and Google uses its own link evaluation. DA correlates with rankings because both are influenced by the same underlying factor: quality backlinks.
DA can be manipulated.Sites can inflate their DA through expired domain purchases, PBN links, or link schemes. Google's SpamBrain detects these manipulations even when DA remains artificially high (Google, 2024).
Google has its own systems. Google uses PageRank (an internal, non-public version), link spam detection, and content quality signals that are far more sophisticated than any third-party metric.

How to Actually Improve Your Domain Authority

While DA itself is not a ranking factor, improving it usually means improving the underlying signals that Google does care about. Here is a practical roadmap:

1. Earn Quality Backlinks

The number-one driver of DA and DR growth. Focus on earning links from relevant, trusted sites in your niche. Websites that consistently publish original research earn 77% more backlinks than those that only publish opinion content (Orbit Media, 2025).

2. Remove Toxic Links

Disavow links from spammy, irrelevant, or manipulative sites. While Google says it ignores most bad links automatically, a clean link profile ensures your authority metrics are accurate reflections of your real strength.

3. Build Internal Link Architecture

Strong internal linking distributes authority from your high-PA pages to newer content. Sites with well-structured internal linking see 40% more pages indexed by Google (Botify, 2024).

4. Publish Consistently

More quality pages mean more opportunities to earn backlinks. Publish content worth linking to: original data, comprehensive guides, useful tools, and expert analysis.

5. Be Patient

DA growth is slow and logarithmic. A new site might go from DA 0 to DA 20 in six months with consistent effort, but jumping from DA 40 to DA 60 can take years. The median DA for sites ranking on page one of Google is 40 (Backlinko, 2024).

Key Takeaways

DA (Moz) and DR (Ahrefs) are third-party scores from 0-100 measuring a domain's backlink strength.
Page Authority matters more than Domain Authority when evaluating individual backlink opportunities.
Google does NOT use DA or DR in its ranking algorithm (Google Search Central, 2024).
DA correlates with rankings because both reflect the same underlying factor: quality backlinks.
DR is logarithmic: each 10-point increase requires exponentially more links than the previous one.
Improve DA by earning quality links, removing toxic links, and building strong internal architecture.

What you will learn