Domain Authority (DA) is a proprietary metric developed by Moz that predicts how likely a website is to rank on search engine results pages. Scored on a scale from 1 to 100, a higher DA suggests stronger ranking potential. The score is calculated using dozens of factors — primarily the number and quality of external backlinks pointing to the domain — using Moz's own link index.

How Domain Authority is Calculated

Moz uses a machine learning model trained to correlate with Google rankings. Key inputs include:

  • Linking root domains: The number of unique websites linking to your domain
  • Quality of those links: Links from high-DA, authoritative sites carry more weight
  • MozRank and MozTrust: Internal Moz scores for link popularity and trustworthiness
  • Spam score: A heavily spammy backlink profile will suppress DA

DA is recalculated frequently as Moz crawls the web and updates its link index. Because the score is relative — calibrated against the entire web — it can drop even if your backlink profile improves, simply because competitors improved faster.

Not a Google metric: Domain Authority is not used by Google and has no direct influence on your actual search rankings. It is a third-party indicator used by SEOs to benchmark sites, evaluate link prospects, and track progress over time.

What is a Good Domain Authority Score?

DA is best interpreted in context rather than as an absolute number:

  • 1–20: New or low-authority sites, few backlinks
  • 21–40: Developing authority, some established links
  • 41–60: Moderate authority, competitive in many niches
  • 61–80: High authority, strong backlink profile
  • 81–100: Very high authority — typically major publications, social platforms, governments

A DA of 40 on a niche gardening blog is very competitive within that niche, even though it looks modest against a DA 90 news site. Always compare your DA against direct competitors in your industry.

Domain Authority vs Domain Rating

DA (Moz) and Domain Rating (Ahrefs) measure similar things but use different datasets and methodologies. Neither is superior — they are different estimates. Most SEOs check both. Other tools have their own equivalents: Semrush uses Authority Score, Majestic uses Trust Flow and Citation Flow.

How to Improve Domain Authority

  • Earn backlinks from high-quality, relevant websites
  • Remove or disavow toxic, spammy links
  • Create linkable assets: research, data studies, tools, guides
  • Build internal links to distribute link equity across the site
  • Be patient — DA improvements happen over months, not days