Definition
Domain Authority (DA) is a metric created by Moz that predicts how well a website will rank in search results, scored on a scale of 1 to 100. It's calculated mostly from the quantity and quality of links pointing to a site. Importantly, it's a third-party estimate, not a number Google uses or publishes.
In depth
Domain Authority and similar scores like Ahrefs' Domain Rating exist because Google doesn't share its own ranking weights. These tools crawl the web, map links, and produce a single comparative number so you can gauge one site against another. The scale is logarithmic, which means moving from 20 to 30 is far easier than moving from 60 to 70, and a new site naturally starts low.
In practice, DA is most useful as a relative benchmark rather than a goal in itself. It helps you judge whether a competitor outranks you because of authority, and whether a site offering you a backlink is worth pursuing. It does not directly cause rankings, so obsessing over the number while ignoring content and intent is a trap.
The mistake we see is treating DA as a scoreboard. WellBuilt uses it as one input among many: a quick read on competitive landscape and link quality, never the target. Rankings, traffic, and leads are what actually matter, and a modest DA site with sharp, intent-matched content routinely beats a higher-DA site that ignored the basics.
The formula
Domain Authority is a 1-100 logarithmic score calculated by Moz from a site's link profile; higher is better and it's easier to grow early than late. Worked example
A new remodeling company's site sits at DA 8 while the area's leading home builder sits at DA 45, which tells us authority is the gap to close, mainly through earning a handful of strong local links over time.
SEO
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