Domain Authority (DA) is a Moz-created score from 1–100 that estimates how well a website will rank in search engines, based primarily on the quality and quantity of its backlink profile. It is not a Google ranking factor — Google does not use DA in its algorithm. It’s a third-party proxy metric useful for competitive benchmarking, not a target to optimize directly.
How Domain Authority Is Calculated
Moz calculates DA using a machine learning model that factors in the number of unique root domains linking to your site, the authority of those linking domains, and link quality signals. The scale is logarithmic — moving from 20 to 30 is easier than 50 to 60.
Ahrefs uses a similar metric called Domain Rating (DR); Semrush uses Authority Score. All three measure backlink profile strength with slight methodological differences. For competitive analysis, pick one and use it consistently.
What DA Scores Actually Mean for Healthcare Practices
How to Improve Domain Authority
DA increases when high-quality sites link to yours. For healthcare practices, the most reliable link acquisition sources are:
What not to do: Buying links, participating in link schemes, or using PBNs (private blog networks). Google penalizes manipulative link practices; in healthcare where YMYL (Your Money or Your Life) standards apply, the scrutiny is higher.
DA vs. DR vs. Authority Score: Which to Use
See how Direction builds healthcare site authority or learn more about dental practice SEO.