What Is My Domain Authority and How Is It Measured?
If you've ever researched SEO or looked at a competitor's website metrics, you've probably encountered the term Domain Authority. It sounds official — like something Google tracks and uses to rank your site. The reality is a bit more nuanced, and understanding what DA actually is (and isn't) matters a lot if you're making decisions about your website strategy.
Domain Authority Is a Third-Party Metric, Not a Google Score
Let's start with the most important clarification: Domain Authority (DA) is not a Google metric. Google does not publish a score called Domain Authority, and it doesn't use that label internally.
DA is a proprietary scoring system created by Moz, the SEO software company. It predicts how likely a website is to rank well in search engine results pages (SERPs), based on a 0–100 logarithmic scale. The higher the score, the stronger the site's perceived authority.
Other SEO platforms have developed their own equivalents:
| Platform | Metric Name | Scale |
|---|---|---|
| Moz | Domain Authority (DA) | 0–100 |
| Ahrefs | Domain Rating (DR) | 0–100 |
| Semrush | Authority Score | 0–100 |
| Majestic | Trust Flow / Citation Flow | 0–100 |
These scores are similar in concept but not identical in calculation. A site might score 45 in Moz and 61 in Ahrefs — both are legitimate signals, just measured differently. None of them is "the" official number.
How Domain Authority Is Actually Calculated
Moz's DA score is derived primarily from link data — specifically the quantity and quality of external websites linking to your domain. The core inputs include:
- Linking root domains — how many unique domains point to your site
- Quality of those links — are they from authoritative, relevant sites or low-quality directories?
- Link profile diversity — a natural mix of sources tends to score better than a concentrated cluster
- MozRank and MozTrust — internal Moz metrics that feed into the final score
The logarithmic scale means it gets significantly harder to climb as you move higher. Going from DA 20 to DA 30 is far easier than moving from DA 70 to DA 80. A brand-new site with no inbound links typically starts at DA 1.
🔍 How to Check Your Domain Authority
You can check DA through several free and paid tools:
- Moz Link Explorer — the original source; free tier allows limited lookups
- MozBar — a browser extension that shows DA while you browse
- Ahrefs, Semrush, or Ubersuggest — show their own equivalent scores
- Bulk DA checkers — third-party sites that pull Moz data via API for multiple URLs at once
Enter your root domain (e.g., example.com) rather than a specific page URL to get the domain-level score. Page-level authority is a separate metric Moz calls Page Authority (PA).
What Factors Push Your Score Up or Down
DA fluctuates — sometimes noticeably — even if you haven't done anything differently. That's because the score is relative to the rest of the web. If many sites in your industry acquire strong links while yours stays static, your DA may drop even though your link profile hasn't changed.
Factors that typically increase DA over time:
- Earning backlinks from high-DA, topically relevant websites
- Publishing content that others genuinely want to reference
- Building a consistent presence through guest posts, press mentions, or partnerships
Factors that can drag DA down:
- A sudden spike in spammy or low-quality inbound links
- Losing high-value links when sites remove or restructure their content
- Disavowing links that were inflating your score artificially
What DA Doesn't Tell You 📊
Domain Authority is a directional indicator, not a guarantee of rankings. A site with DA 55 doesn't automatically outrank one with DA 40 — Google's actual ranking algorithm considers hundreds of factors including content relevance, page experience, search intent match, and technical health.
DA is most useful as a comparative tool:
- Benchmarking your site against competitors in your niche
- Evaluating potential link partners (is this site worth pursuing?)
- Tracking your own growth trend over time
It's a weaker tool for predicting whether a specific page will rank for a specific keyword.
The Variables That Shape What DA Means for Your Site
What counts as a "good" DA score depends heavily on context:
- A local service business competing in a regional market might perform well organically with a DA of 20–35, because local competitors are often in a similar range
- A B2B SaaS company competing for high-volume industry keywords may need a much stronger profile to appear alongside established publications
- A brand-new blog starting at DA 1–5 isn't in trouble — that's normal, and the score reflects age and link volume, not content quality
- A large media site or established brand might carry DA 70+ built over years of press coverage and editorial links
Your industry's competitive landscape, the age of your domain, the volume of content you've published, and how actively you've pursued link-building all interact to shape where your score sits and what it means in practice.
That relationship between your score and what it actually implies for your rankings is the piece no general guide can fully resolve — it depends on who you're competing against, what keywords matter to your business, and what your current link profile actually looks like beneath the headline number.