Domain Authority: What It Is, How It Works, and What Score You Need

1. What Is Domain Authority?

Domain Authority is a prediction, not a ranking factor. Moz trains its DA model against real Google search results, so a site with DA 70 tends to outrank a site with DA 30 for the same query, all else equal. The score summarizes one input above all others: link equity, the ranking value that backlinks pass from one site to another.

The concept traces back to PageRank, the algorithm Larry Page and Sergey Brin built at Stanford in 1998. PageRank scores each page by counting links to it and weighting each link by the authority of the linking page. Moz DA, Ahrefs Domain Rating (DR), and DataForSEO Domain Rank all apply the same core idea at the domain level.

In practice, SEOs use Domain Authority for three jobs: benchmarking a site against competitors, screening prospects for link building campaigns, and tracking whether a backlink strategy is working over months.

Two definitions keep the rest of this guide precise. A backlink is a hyperlink from another website to yours; a referring domain is a unique website that hosts at least one of those backlinks. Authority metrics count referring domains far more heavily than raw backlink totals, because a thousand links from one site prove one relationship, while a thousand referring domains prove a thousand independent endorsements.

2. How Is Domain Authority Calculated?

The single strongest input is referring domains, the count of unique websites that link to you. One hundred links from one blog count as one referring domain. One hundred links from one hundred separate news sites count as one hundred referring domains, and they move DA far more.

The logarithmic scale matters for planning. A logarithmic scale compresses large numbers, so each additional point requires roughly ten times more link equity than the point before it. A site can jump from DA 10 to DA 25 with fifty good referring domains. Reaching DA 60 can require thousands.

Three inputs drive most of the score:

• Referring domain count. Unique linking websites, the highest-weight input across Moz, Ahrefs, and DataForSEO.
• Referring domain authority. A link from a DR 90 news site passes more link equity than fifty links from DR 5 directories.
• Link profile quality. Dofollow ratio, anchor text diversity, and spam score adjust the raw link counts up or down.

Why the scale is logarithmic

Link distribution across the web follows a power law: a small number of domains, such as Wikipedia and YouTube, hold billions of backlinks, while the median website holds a few dozen. A linear 0 to 100 scale would cram almost every site into the bottom two points. The logarithmic transform spreads ordinary sites across the usable range, at the cost of making each higher point exponentially harder to earn.

3. Domain Authority vs Domain Rating vs Domain Rank: What Is the Difference?

Each vendor runs its own web crawler, so each sees a different slice of the link graph. That is why the same domain can show DA 45, DR 62, and Domain Rank 480 at the same time. Here is how the three metrics compare:

Ahrefs DR ignores spam signals and anchor text; it measures only dofollow link equity. Moz DA blends in Spam Score and ranking correlations, so DA reacts to link quality problems that DR ignores. DataForSEO Domain Rank uses the wider 0 to 1000 scale, which gives tools finer granularity between similar domains. Divide Domain Rank by ten for a rough 0 to 100 equivalent.

Pick one metric and track it consistently. Switching between DA and DR mid-campaign creates noise that looks like progress or decline when nothing changed. If your tool stack spans vendors, record all three scores at the start of a campaign so every later reading has a same-vendor baseline.

One more difference matters for interpretation: index size and refresh speed. Ahrefs refreshes its crawl continuously and tends to surface new links within days. Moz updates DA on roughly monthly cycles. DataForSEO exposes Domain Rank through an API, which is why bulk tools and SEO platforms, including this site's own checker, often report Domain Rank behind the scenes.

4. What Is a Good Domain Authority Score?

Absolute tiers only make sense as rough context, because a DA 35 site can dominate a local niche while a DA 55 site struggles in finance. Use this tier table as a starting point:

The practical benchmark: pull the DA of the ten sites ranking for your primary keyword. If your score sits within about ten points of the median, your content and on-page work can close the gap. If you trail by twenty points or more, you need a deliberate plan to increase your Domain Authority before rankings follow.

5. Does Google Use Domain Authority?

Google representatives, including John Mueller and Gary Illyes, have stated repeatedly that Google has no single sitewide authority score it exposes or that matches DA. Google's link systems evaluate per-page signals: which pages link to a URL, the authority of those pages, the anchor text, and the topical relevance of the linking context.

So why does DA still correlate with rankings? Because DA and Google both read the same underlying evidence, the link graph. A domain with strong backlinks tends to host pages with strong backlinks. The correlation is real; the causation is not. Chasing the number without earning real links, for example by buying high-DA links from irrelevant sites, moves the metric without moving rankings.

The per-page distinction has a practical consequence: a weak page on a strong domain does not inherit the domain's full authority. Google ranks the page, informed by the links pointing at that page and the internal links feeding it. Sitewide authority helps new pages get crawled and trusted faster, but page-level link equity still decides competitive rankings.

Treat Domain Authority as a thermometer, not a thermostat. It reads the temperature of your link profile. It cannot set it.

6. How Do You Check Your Domain Authority?

A useful check covers four data points, not one:

1. Your authority score, as the baseline to track monthly.
2. Your referring domain count, the input that actually moves the score.
3. Competitor scores for the same keyword set, to size the gap.
4. Your backlink profile, via a free backlink checker, to see which links create the score.

Recheck monthly, not daily. Authority metrics update on crawler cycles, and the logarithmic scale means visible movement takes weeks of earned referring domains.