Domain Authority (DA) is a score developed by Moz that predicts how well a website is likely to rank in search engine results. It runs on a scale from 1 to 100; higher scores indicate stronger ranking potential. DA isn’t a metric used by Google itself, but it’s widely used in the SEO industry as a proxy for website credibility and link-building value.

How Domain Authority is Calculated

DA is calculated using dozens of factors, but the most significant is the quantity and quality of inbound links pointing to your domain. A backlink from a high-DA site like Forbes carries far more weight than a link from a new blog with no traffic. Moz’s algorithm also considers linking root domains, the overall link profile health, and spam indicators.

Why DA Matters for Business Owners

When you’re building an online business, DA affects several things. Acquiring an expired domain with a DA of 30 gives you a head start over starting from zero. When doing outreach for backlinks or guest posts, the DA of the target site tells you how much value that link will bring. For anyone building niche sites, content businesses, or domain portfolios, DA is one of the core metrics to track alongside organic traffic.

DA vs. DR vs. Google’s Own Signals

Domain Authority is Moz’s metric. Ahrefs has a similar metric called Domain Rating (DR). These are third-party scores and Google uses neither directly. That said, high DA sites tend to rank well because they’ve earned the same trust signals Google values: quality backlinks, consistent content, and low spam scores. Use DA as a directional tool, not an absolute truth.

How to Improve Your Domain Authority

Building DA takes time and consistent effort. Earn backlinks from reputable sites through quality content, guest posting, and digital PR. Remove or disavow toxic links that drag your score down. Improve your site’s technical health so search engines can crawl and index you efficiently. There are no shortcuts; services promising to sell DA improvements are almost always link farms that can get your site penalized.

The Bottom Line

Domain Authority is a useful benchmark for gauging the competitive strength of a website in organic search. Focus on earning quality links and creating valuable content, and your DA will reflect that work over time. Start your SEO education with the full SEO guide in the library.