Domain Rating (Ahrefs), Domain Authority (Moz), and Authority Score (Semrush) all try to answer the same rough question, how strong is this site’s backlink profile, but each one runs its own algorithm on its own independently crawled link data. None of them is a metric Google uses for crawling, indexing, or ranking. Because each company builds its methodology from a different dataset, a DR of 60 and a DA of 60 are not measuring the same thing, and there is no reliable formula for converting one into the other.
What actually differs between the three:
What Domain Rating (Ahrefs) Actually Measures
Ahrefs defines it plainly: “Domain Rating (DR) shows the strength of a website’s backlink profile compared to the others in our database on a 100-point scale.”
The calculation works like a domain-level version of PageRank. Ahrefs finds every domain with at least one followed link to the target site, checks how many other domains each of those linking domains also links out to, and passes a share of authority through each connection, described in Ahrefs’ own terminology as “link juice” that a domain “splits … equally amongst the domains it links to.” The result is scaled to the 0-100 range.
Ahrefs itself notes that “while DR correlates with Google rankings pretty well, it doesn’t do this as well as our URL Rating (UR),” its page-level equivalent. Ahrefs is also direct about what DR is not a substitute for: “Google ranks pages, not websites,” and “although DR correlates strongly with a website’s search traffic, you should not focus your efforts on growing this metric specifically.”
What Domain Authority (Moz) Actually Measures
DA is calculated with a machine-learning model built primarily on backlink data pulled from Moz’s own Link Explorer web index, using, in Moz’s words, “dozens of factors in its calculations.” Because it depends on Moz’s independently built index, a DA score changes for two separate reasons: Moz updating its crawl of the web’s links, or Moz updating the DA scoring model itself, most notably the 2019 rollout of Domain Authority 2.0.
Moz is explicit that DA is not what Google uses to rank sites: “Domain Authority is not a Google ranking factor and has no effect on the SERPs,” and elsewhere, “Domain Authority is not a direct ranking factor.” Moz frames DA as a relative benchmarking tool, useful for comparing your own site against competitors over time, not an absolute score of quality.
Semrush Authority Score: A Third Approach
Semrush’s Authority Score takes a broader input set than either DR or DA. Semrush describes it as “our compound metric that grades the overall quality of a website or a webpage,” on “a scale of 1 to 100 so the closer the Authority Score is to 100 the better.” It’s “calculated from eight weighted factors” spanning three areas: link power, organic traffic, and a set of spam-pattern indicators (unnatural dofollow ratios, referring domains sharing the same IP, and similar signals).
Authority Score differs from DR and DA in one clear way: Semrush explicitly names organic traffic and spam-pattern detection as separate components of the score, rather than deriving the whole number from backlink data alone. Semrush’s own guidance is to use it comparatively: Authority Score is “best used for domain comparison, and not for determining good/bad on an absolute scale.”
Why the Same Site Gets a Different Score From Every Tool
Two things diverge before any algorithm even runs. First, the raw data: Ahrefs, Moz, and Semrush each operate their own web crawler and build their own independent index of links. Each tool inevitably sees a different, overlapping-but-not-identical slice of the web’s backlinks. Second, the math: Ahrefs computes DR as a link-flow calculation between domains; Moz trains a machine-learning model on its own index plus dozens of additional factors; Semrush blends link power with organic traffic and spam signals into a weighted composite.
Neither the input data nor the scoring formula is shared or standardized across vendors, so there’s no dependable conversion between a DR score and a DA score for the same domain, and treating “DR 45” and “DA 45” as equivalent misreads what each number is built from. The only comparisons that hold up are same-tool comparisons: your DR against a competitor’s DR, or your DA against a competitor’s DA, not one metric against the other.
Does Google Use Any of These Scores?
No, and Google has said so repeatedly. Search Engine Land’s own review of Domain Authority quotes Google’s Gary Illyes on third-party authority metrics: “We don’t use it, and it doesn’t align with anything we have at Google.” The same piece cites a statistician’s independent analysis finding DA’s correlation with first-page rankings was “0.001 for positions 1 through 5 and 0.011 for positions 6 through 10,” essentially no measurable relationship. This lines up with what Ahrefs and Moz say about their own metrics: Ahrefs states that Google ranks pages, not websites, and Moz states plainly that DA “has no effect on the SERPs.”
That doesn’t make DR, DA, or Authority Score useless. It means they’re proxies for backlink strength as each vendor defines it, not a leaked Google signal, and they should be read that way.
How to Use These Scores When Vetting a Site’s Links
The practical use case for any of these three scores is comparison, not verdict. When you’re deciding whether a prospective link is worth pursuing, or reviewing links you already have, a DR or DA figure tells you roughly how well-linked the source domain is relative to others in the same tool’s index. It doesn’t tell you whether that link is still live, still carrying the rel attribute you expect, or actually relevant to your site, and those are the things that decide whether a link is helping or doing nothing. For a fuller picture of what makes a link worth having beyond a single authority number, including anchor text and dofollow ratios, see what a healthy backlink profile looks like.
This is also where authority scores fit into an audit of a profile you already built. A high DR or DA on a page that links to you is a reasonable input when you’re triaging which links matter most, but it’s not a substitute for checking the link itself. Tools built for verifying and monitoring links you already have, including BacklinkTower, check whether a specific backlink is still live, still dofollow, and still pointing where it should, the kind of per-link status that a domain-level authority score can’t tell you on its own. The audit checklist walks through where authority metrics fit alongside those per-link checks. And since DR, DA, and Authority Score are all built on top of referring domains rather than raw backlink counts, understanding what referring domains actually measure helps explain why a site with fewer, stronger referring domains can outscore one with a larger but weaker link count.
DR vs. DA vs. Authority Score at a Glance
| Domain Rating (Ahrefs) | Domain Authority (Moz) | Authority Score (Semrush) | |
|---|---|---|---|
| Scale | 0-100 | 1-100 | 1-100 |
| Primary input | Link-flow calculation between domains | Machine learning on Moz’s backlink index | Link power + organic traffic + spam signals |
| Includes traffic data? | No | Not specified as a named input | Yes, explicitly |
| Includes spam detection? | No | No | Yes, explicitly |
| Google ranking factor? | No | No, per Moz’s own documentation | No |
| Best used for | Comparing link strength within Ahrefs’ index | Benchmarking against competitors over time | Domain comparison, not absolute quality |
Frequently Asked Questions
Is a Domain Rating of 50 the same as a Domain Authority of 50?
No. DR and DA are built from different link indexes and different algorithms, so identical numbers don’t represent identical link profiles. Ahrefs computes DR from its own crawl of the web using a link-flow calculation; Moz computes DA with a machine-learning model trained on its own separate index. Compare DR against other DR scores and DA against other DA scores, not against each other.
Does Google use Domain Rating or Domain Authority to rank websites?
No. Google’s Gary Illyes has stated directly that Google doesn’t use third-party authority metrics and that they don’t align with anything Google has internally. Moz’s own documentation confirms Domain Authority has no effect on search results, and Ahrefs is explicit that Google ranks pages, not websites. These are third-party proxies for backlink strength, not Google signals.
Which is more accurate, DR or DA?
Neither is “more accurate” in an absolute sense, because they’re not measuring against the same standard. Ahrefs itself notes that DR correlates with rankings less reliably than its own page-level URL Rating metric, and an independent statistical analysis found DA’s correlation with first-page rankings was close to zero. Both are best treated as comparative tools within their own tool, not predictive scores.
Can I convert my Domain Rating into an equivalent Domain Authority score?
Not reliably. There’s no published, vendor-endorsed formula for converting one into the other because the underlying link indexes and scoring algorithms differ. Any online “DR to DA converter” is applying an approximation, not a verified equivalence. If you need both numbers, check each tool directly rather than estimating one from the other.
Why did my Domain Authority change even though I didn’t gain or lose any backlinks?
Moz’s own documentation lists two causes unrelated to your own link-building activity: updates to Moz’s web index, which can surface more or fewer linking domains from a fresh crawl, and updates to the DA scoring model itself, such as the 2019 rollout of Domain Authority 2.0. A shift in your competitors’ scores can also move your relative position even if your own profile hasn’t changed.
What counts as a “good” score on any of these metrics?
There’s no fixed threshold that applies everywhere, since all three scores are comparative by design. Semrush states its Authority Score is “best used for domain comparison, and not for determining good/bad on an absolute scale,” and the same logic applies to DR and DA. The useful comparison is against the sites currently ranking for the keywords you’re targeting, using the same tool for both your score and theirs.
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