DR, DA, TF/CF: Domain Authority Metrics Explained for 2026
DR, DA, TF/CF: Domain Authority Metrics Explained for 2026
There is no direct access to Google's ranking algorithm. Third-party tools — Ahrefs, Moz, Majestic — build proxy metrics by crawling the web independently and computing their own link graphs. These metrics approximate link authority but do not measure it with precision. Using them correctly means treating them as initial filters for prioritization, not as definitive purchase decisions. A domain that scores well on all three tools requires further manual verification. A domain that fails on any one of them requires a specific reason to override the flag.
This guide explains how each metric is calculated, what it does and does not capture, where manipulators exploit the gap, and how to combine metrics into a practical scoring framework for domain acquisition.
Why Domain Metrics Exist
Google's link scoring is a private computation. PageRank — the original link-based ranking signal — has not been publicly updated since 2016. What operators see in Ahrefs, Moz, and Majestic are independent approximations built from each tool's own crawler crawling billions of pages and scoring links based on the company's own algorithmic interpretation.
Each tool makes different choices:
- Ahrefs weights link volume and the DR of linking domains
- Moz weights link quality signals and penalizes spam indicators
- Majestic weights proximity to a curated seed set of trusted sources
The same domain can show DR 52, DA 38, and TF 22 simultaneously — three different numbers reflecting three different methodologies applied to the same set of backlinks. Each number provides a different angle on the same reality. Using only one tool means missing the insights the others provide.
The practical value of metrics: They reduce vetting time. A database of 10,000 candidate domains becomes a list of 200 viable candidates in 20 minutes with the right metric filters applied. The risk: treating a metric output as a conclusion rather than a starting point for deeper analysis.
Ahrefs Domain Rating (DR) — Full Explanation
Domain Rating (DR) is Ahrefs' measure of the strength of a domain's backlink profile relative to all other domains in Ahrefs' index. It is displayed on a logarithmic 0–100 scale.
How DR Is Calculated
The calculation has three inputs:
- Unique linking domains: how many distinct domains link to the target domain with at least one dofollow link
- DR of each linking domain: domains with higher DR contribute more to the target's score
- Equity dilution: how many external dofollow links the linking domain has. A DR 60 domain that links to 500 other sites contributes less per link than a DR 60 domain that links to 5 sites
The logarithmic scale means the distance between DR 80 and DR 90 represents far more accumulated authority than the distance between DR 10 and DR 20. A DR 40 domain is not "twice as strong" as DR 20 — it is orders of magnitude stronger in link volume terms.
What DR Does Not Measure
This is the most operationally important caveat:
- Topical relevance: a DR 60 domain from a cooking blog carries the same DR number as a DR 60 domain from a sports news site — but they contribute different topical equity to different campaign types
- Anchor text quality: DR says nothing about what anchors are being used by the incoming links — excessive exact match or pharmaceutical anchors are invisible in the DR score
- Spam indicators: DR can be artificially inflated by high-volume low-quality link networks — the score rises because it counts any dofollow link from a domain with any DR score
- Editorial quality: whether the links are genuine editorial endorsements or paid/placed links is not reflected in DR
- Recency: a DR 45 domain that had 200 referring domains in 2019 and now has 50 still shows approximately DR 45 until Ahrefs recrawls and updates — scores lag behind reality by days to weeks
DR Benchmarks for Domain Acquisition
| Use case | Minimum DR | Preferred range | Notes |
|---|---|---|---|
| Tier 2 PBN links | 20 | 25–35 | Lower cost, volume play |
| Tier 1 PBN links | 35 | 40–55 | Primary authority transfer |
| Expired domain for money site rebuild | 40 | 45–65 | Full history analysis required |
| Competitive niche DR 65+ required | 55 | 60–75 | High cost, high impact |
Spending above $300 on a domain? The cost justification disappears if the supporting TF and Wayback history do not align with the DR.
Moz Domain Authority (DA) — Full Explanation
Domain Authority is Moz's 0–100 logarithmic metric predicting a domain's likelihood of ranking in search results relative to other domains. It is computed by a machine learning model that incorporates Moz's own link data alongside additional quality signals.
How DA Is Calculated
DA incorporates:
- MozRank: link popularity weighted by the quality of linking domains (analogous to DR)
- MozTrust: a quality-weighted score that models proximity to high-trust domains — similar in concept to Majestic's TF
- Spam detection: Moz applies its own spam signal detection, which penalizes domains with high proportions of low-quality inbound links
- Link diversity: diversity of anchor text, link types (dofollow/nofollow), and referring TLDs
The machine learning model recalibrates monthly based on Moz's crawl data and Google Search result correlations. This monthly recalibration is why DA can move ±5–10 points without any change in the domain's actual link profile.
DA vs DR: The Key Differences
| Dimension | DR (Ahrefs) | DA (Moz) |
|---|---|---|
| Update frequency | Near real-time | Monthly |
| Spam sensitivity | Low — counts most dofollow links | High — penalizes spam patterns |
| Volatility | Stable | High (monthly swing ±5–10) |
| Topical awareness | No | Partial (via MozTrust quality signals) |
| Manipulation resistance | Moderate | Higher |
The DA gap test: If DR is 50 and DA is 30, the 20-point gap signals that Moz is penalizing something Ahrefs is counting. Run the spam analysis — this divergence pattern almost always indicates either a history of bulk low-quality links, a past spam campaign, or purchased traffic from link farms that Moz has flagged.
Moz Spam Score
Separate from DA, Moz provides Spam Score (0–17 flags or as a percentage). It models the correlation of a domain's characteristics with manually penalized sites in Moz's training set.
Thresholds for domain acquisition:
- Spam Score ≤ 5% (≤ 1 flag): clean, no concern
- Spam Score 6–10%: investigate — check specific flags in Moz's on-page analysis
- Spam Score 11–30%: caution — only proceed if there is a clear, specific explanation for the flags (e.g., the domain has few total pages — a common false positive for small legitimate sites)
- Spam Score > 30%: hard reject for PBN use
Spam Score false positives exist: very new domains or domains with minimal total pages often score higher than their actual risk warrants. Cross-reference with Majestic TF:CF and Ahrefs anchor text distribution before rejecting a domain based solely on Spam Score.
Majestic Trust Flow (TF) and Citation Flow (CF) — Full Explanation
Majestic's Trust Flow and Citation Flow are separate but related metrics that together provide the most operationally useful quality signal for expired domain vetting.
Trust Flow (TF)
Trust Flow measures a domain's link profile quality by computing proximity to Majestic's seed set — approximately one million URLs from established, trusted sources: major media outlets, government sites, educational institutions, and widely-cited editorial publishers.
The algorithm propagates trust outward from seed URLs: sites directly linked to by seed URLs carry high TF; sites linked to by those sites carry moderate TF; the signal attenuates with each hop. This means TF does not inflate with link volume — adding 1,000 forum profile links does not materially raise TF because forum profiles are distant from the seed set.
TF practical benchmarks:
| TF Range | Interpretation |
|---|---|
| TF ≥ 30 | High-quality link profile, editorial-heavy |
| TF 20–29 | Good quality, viable for tier 1 PBN |
| TF 15–19 | Acceptable, verify anchor profile |
| TF 10–14 | Below average — use for tier 2 only |
| TF < 10 | Poor quality, do not use for tier 1 |
Citation Flow (CF)
Citation Flow measures link volume — how many links point at a domain — without weighting for quality. A domain can achieve CF 50 entirely from comment spam and forum profiles. CF in isolation is meaningless for quality assessment.
CF's operational value is as the denominator in the TF:CF ratio.
TF:CF Ratio — The Most Important Single Metric
The TF:CF ratio expresses how much trust is associated with the link volume. A ratio approaching 1.0 means that nearly every link pointing at the domain came from a high-trust source — virtually impossible in practice. Healthy editorial profiles sit between 0.4 and 0.7.
Decision rules:
| TF:CF Ratio | Action |
|---|---|
| ≥ 0.6 | Strong buy signal — proceed to Wayback and anchor review |
| 0.45–0.59 | Acceptable — investigate CF sources (what is driving volume?) |
| 0.3–0.44 | Caution — high probability of historical spam campaigns |
| < 0.3 | Hard reject for PBN use |
A DR 55 domain with TF:CF of 0.25 is unusable for tier 1 PBN links regardless of the DR score. The DR reflects link count; the TF:CF reveals that those links came from low-trust sources. Majestic's seed set does not respect them, and neither will Google's quality signals in the longer term.
Topical Trust Flow (Topical TF)
Topical Trust Flow categorizes the trust signal by topic area. Majestic assigns each domain a primary and secondary Topical TF category based on the topics of the highest-trust linking sites.
Why topical TF matters for expired domains:
A domain with TF 25 and 80% topical TF in "Sports" passes high-trust equity specifically for sports-related campaigns. The same domain placed in a legal industry campaign passes less effective topical equity despite the equivalent numerical TF.
For PBN-quality domain purchases:
- Check the top 3 Topical TF categories in Majestic Site Explorer
- The primary category should align with your money site's niche at the category level
- Broad categories (News, Society, Business) are less valuable for topical transfer than specific categories (Sports, Finance: Investing, Health: Medicine)
How Metrics Are Gamed: Detection Methods
Understanding manipulation patterns protects against overpaying for inflated domains.
DR Inflation
Method: an operator creates a private network of sites, uses each to cross-link the others, and builds artificial DR across all simultaneously.
Detection:
- DR is high but TF is disproportionately low (TF < 15 on a DR 45+ domain)
- Referring domains are mostly domains with no real content (check by opening the top 20 linking domains)
- The linking domains all have similar DR ranges and registration dates
- No recognizable publications or editorial sites in the referring domain list
Temporary Link Stacking
Method: a seller acquires links into a domain for 30–60 days before selling, then removes them after the sale is complete. DR score inflates, then collapses post-sale.
Detection:
- Ahrefs "new referring domains" chart shows an unnatural spike in the past 60–90 days with no corresponding content event (no press coverage, no major publication)
- The referring domain additions are recent, generic, and from low-content domains
Historical Spam Cleanup Attempts
Method: a domain has a toxic backlink history; the operator builds new quality links to dilute the spam ratio before listing.
Detection:
- Moz Spam Score remains elevated despite good current metrics
- Majestic anchor text distribution shows residual pharmaceutical/financial/adult anchors in the historical anchor cloud
- The domain appears on industry-specific spam blacklists
The Complete Domain Scoring Framework
A standardized evaluation process for every domain purchase decision:
Step 1 — Metric Floor Filter (Pass/Fail)
Apply these four filters as absolute gates:
- DR ≥ 30 (tier 2) or DR ≥ 40 (tier 1)
- TF ≥ 10 (tier 2) or TF ≥ 15 (tier 1)
- TF:CF ≥ 0.40 (minimum) or ≥ 0.50 (preferred)
- Moz Spam Score ≤ 15%
Any domain failing these gates is rejected. No exceptions based on deal price or seller claims.
Step 2 — Metric Quality Scoring
Score the following on a 0–3 scale and sum the points:
| Factor | 0 pts | 1 pt | 2 pts | 3 pts |
|---|---|---|---|---|
| DR | < 30 | 30–39 | 40–54 | 55+ |
| TF | < 10 | 10–19 | 20–29 | 30+ |
| TF:CF | < 0.3 | 0.3–0.44 | 0.45–0.59 | ≥ 0.6 |
| Topical TF match | No match | Adjacent | Related | Direct match |
| Spam Score | > 15% | 10–15% | 5–10% | < 5% |
Score interpretation:
- 12–15: strong candidate — proceed to steps 3–4
- 8–11: acceptable — run deeper manual check before purchasing
- Below 8: likely pass
Step 3 — Referring Domain Timeline Check (Ahrefs)
- Open the "referring domains" timeline in Ahrefs for the past 3 years
- Pattern A (pass): gradual growth or flat stability
- Pattern B (flag for review): spike in last 90 days without obvious news context
- Pattern C (reject): spike followed by sharp decline — link stacking and removal pattern
Step 4 — Wayback Machine History
- Confirm: at least 24 months of snapshots with content consistency
- Confirm: no gaps longer than 12 months
- Confirm: content topic in Wayback archives matches the claimed niche and the Topical TF category
Step 5 — Manual Anchor Text Review
- Open top 20–30 anchors in Ahrefs or Majestic
- Flag: more than 15% exact-match keyword anchors targeting obvious spam verticals (online pharmacy, payday loans, adult content)
- Flag: anchor text that reveals the domain was previously used in an obvious SEO campaign for an unrelated niche
- If clean: purchase approved
Using Multiple Metrics Together: Worked Examples
Example A — Safe buy:
- DR 48, DA 40, TF 22, CF 38, TF:CF 0.58, Spam Score 4%
- Topical TF: Sports 55%, News 25%
- Wayback: 6-year continuous sports review site, no gaps
- Verdict: strong tier 1 candidate for sports-adjacent campaigns
Example B — Reject despite good DR:
- DR 52, DA 30, TF 10, CF 45, TF:CF 0.22, Spam Score 8%
- Topical TF: Business 40%, Shopping 30%, Adult 10%
- Verdict: DR inflation — TF:CF 0.22 is a hard reject. Adult Topical TF anchor is a further disqualifier.
Example C — Borderline case:
- DR 44, DA 38, TF 17, CF 35, TF:CF 0.49, Spam Score 7%
- Topical TF: Health 45%, Science 25%
- Wayback: 4-year health information site, one 8-month gap in 2020
- Verdict: acceptable for tier 2 use; for tier 1 deployment against a health-adjacent niche, perform manual anchor review before committing.
Related Reading
Metric Comparison: Quick Reference Table
| Metric | Tool | Scale | What it measures | Update frequency | Manipulation risk |
|---|---|---|---|---|---|
| DR | Ahrefs | 0–100 log | Link profile volume + quality weighting | Real-time | Moderate |
| DA | Moz | 0–100 log | ML-predicted ranking likelihood | Monthly | Low |
| TF | Majestic | 0–100 | Link quality via trust seed proximity | Crawl-dependent | Very low |
| CF | Majestic | 0–100 | Link volume without quality weight | Crawl-dependent | High |
| Spam Score | Moz | 0–17 or % | Correlation with manually penalized sites | Monthly | N/A |
How Metrics Change After Domain Expiration
When a domain expires and is dropped, its metrics do not immediately reset. There is a delay of days to weeks before crawlers revisit and update scores. But the authority itself — the equity carried by the backlinks — does persist through a reasonable expiration period. How long?
- DR: Remains stable for 6–18 months post-expiration as long as referring domains continue linking to the dead URL (and Google continues crawling those linking pages)
- TF: Persists similarly; Majestic's crawl cycle determines when TF refreshes
- Historical vs Fresh Index (Majestic): Majestic distinguishes between Historic TF (all-time) and Fresh TF (last 90 days). A domain that has been expired for 12 months will show higher Historic TF than Fresh TF as fresh links decay from referrer pages
The "authority decay window" for expired domains is generally considered to be 24–36 months without active content. Beyond that point, referring domain counts drop substantially as linking pages are updated, cleaned, or removed, and the metric scores follow.
Practical implication: Buying an expired domain that has been in a parked or dropped state for more than 36 months carries higher risk of metric decay. Check both Majestic's Fresh and Historic TF — if Historic TF is significantly higher than Fresh TF, the decay process has already begun. The Fresh TF is the more reliable indicator of what you are actually purchasing.
Using Metrics to Set Domain Price Anchors
Understanding metrics lets you evaluate whether a domain's asking price is justified:
| DR range | TF range | Expected price range | Notes |
|---|---|---|---|
| DR 25–35 | TF 10–18 | $60–$150 | Tier 2 use, low-competition markets |
| DR 35–45 | TF 15–25 | $150–$400 | Entry tier 1, niche-appropriate |
| DR 45–55 | TF 20–30 | $350–$800 | Strong tier 1, competitive niches |
| DR 55–65 | TF 25–40 | $700–$1,800 | Premium tier 1, high-competition |
| DR 65+ | TF 35+ | $1,500–$5,000+ | Elite, high-demand at auction |
Note: topical alignment multiplies effective value. A DR 45 / TF 22 domain with 80% Sports topical TF and a clean sports publishing history is worth more than the table price for a sports campaign — and less than that price for an unrelated vertical.