What is Domain Authority and How is it Calculated?
Domain authority is a score that predicts how well a site ranks in search engines. Here is how it works, what counts as good, and how to check yours.
16 May 2026 · 6 min read
Domain authority (DA) is a score developed by Moz that predicts how likely a website is to rank in search engine results pages. It runs on a scale of 1 to 100. The higher the score, the more authoritative the site is considered to be relative to others.
Domain authority is not a Google ranking factor. Google does not use Moz's score when deciding where pages rank. But it is a widely used proxy for a site's overall link strength, and it correlates reasonably well with real-world ranking ability, which is why SEOs use it for competitive analysis, link prospecting, and backlink audits.
How is domain authority calculated?
Moz calculates domain authority using a machine learning model that considers hundreds of link-based factors. The most significant are:
- Linking root domains: the number of unique domains linking to the site (not total backlinks)
- Quality of those links: links from high-authority sites carry more weight than links from low-authority sites
- Spam score of linking domains: links from spammy or low-quality sites can drag the score down
- Site's own link profile: the ratio of followed to nofollowed links, anchor text distribution, and link growth over time
DA is calculated logarithmically. Moving from 20 to 30 is easier than moving from 70 to 80. Scores at the top of the scale are increasingly difficult to improve because you are being compared to the highest-authority sites on the internet.
Domain authority vs domain rating vs authority score
Moz, Ahrefs, and Semrush each have their own version of this metric. They use different datasets and different methodologies, so the scores are not directly comparable.
| Metric | Tool | Scale | What it measures |
|---|---|---|---|
| Domain Authority (DA) | Moz | 1–100 | Predicted ranking strength based on link profile |
| Domain Rating (DR) | Ahrefs | 0–100 | Strength of a site's backlink profile |
| Authority Score | Semrush | 1–100 | Organic traffic, backlink quality, and spam signals |
For most practical purposes (link prospecting, competitive analysis, backlink audits), any of these metrics will give you useful directional data. The specific score matters less than consistency: pick one tool and use it throughout your analysis.
What is a good domain authority score?
DA is relative, not absolute. A DA of 30 might be very competitive in a niche industry and completely uncompetitive in others. The number only means something in context.
Rough benchmarks:
| DA range | Typical profile |
|---|---|
| 1–20 | New site or very limited backlink profile |
| 21–40 | Small or niche site with some established links |
| 41–60 | Established site with a decent backlink profile |
| 61–80 | Strong site with significant editorial coverage or domain age |
| 81–100 | Major publishers, government sites, global brands |
Rather than comparing your DA to a fixed benchmark, compare it to the sites ranking for your target keywords. If the top-ranking pages for a keyword have a DA of 40–50, that tells you more than any absolute threshold.
How to check domain authority
You can check domain authority for any website using Crawly's free domain authority checker. Enter any URL and you will see the site's authority score, referring domains, and backlink count instantly, with no login required.
For checking multiple sites at once, the bulk DA checker accepts up to 100 domains and returns scores for all of them in one go. This is useful for link prospecting: paste in a list of potential link partners and filter by authority threshold.
To compare two specific sites side by side, use the domain authority comparison tool.
What is spam score?
Spam score is a Moz metric that estimates how likely a domain is to be penalised by Google. It is calculated by comparing a site's characteristics against known patterns from penalised sites.
A high spam score on a site linking to you does not automatically mean those links are harmful, but it is a signal worth investigating during a backlink audit. Use Crawly's spam score checker to check any domain before pursuing a link from it. For a full explanation of how the metric works and what the thresholds mean, see what is spam score.
Can you improve your domain authority?
Yes, but only indirectly. Domain authority is an output of your link profile, not something you optimise directly. For a full step-by-step breakdown, see how to increase your domain authority. The short version:
- Earn links from high-authority domains: one link from a DA 70 site is worth more than fifty links from DA 10 sites
- Diversify your referring domains: 500 links from 500 different sites is stronger than 500 links from the same site
- Remove or disavow toxic links: links from penalised or spammy sites can pull your score down. See how to build a disavow file
- Build content worth linking to: original data, research, tools, and comprehensive guides attract links naturally
- Be patient: DA changes slowly. Link building is a long-term activity
Domain authority and backlink audits
When conducting a backlink audit, DA (or DR or Authority Score) is one of the primary filters for evaluating link quality. High-DA sites linking to you are assets. Low-DA sites with a high spam score are worth investigating.
For a full picture of your backlink profile, including referring domains, anchor text distribution, and link growth, see how to read a backlink profile.
Domain authority is a useful compass, not a precise measurement. Use it to understand your link profile relative to competitors, prioritise link building targets, and audit incoming links, not as an end goal in itself.
Check your domain authority for free with Crawly's DA checker.