What is Page Authority Calculator?
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Page Authority (PA) is a logarithmic score developed by Moz that predicts how likely a specific webpage is to rank in search engine results pages (SERPs), on a scale of 1 to 100. Unlike Domain Authority (DA) which evaluates an entire domain, Page Authority focuses on the ranking strength of an individual URL — making it useful for comparing specific pages, evaluating the SEO strength of content assets, and identifying which pages have accumulated the most link equity. Page Authority is calculated using a machine learning model trained on thousands of actual search results, incorporating dozens of signals — primarily the quantity and quality of external links pointing to that specific page, the internal link equity flowing to it from the rest of the site, and the domain-level authority of the hosting domain. The logarithmic scale means improvement becomes progressively harder: moving from PA 20 to PA 30 is far easier than moving from PA 70 to PA 80. Page Authority is a proprietary Moz metric and closely mirrors Ahrefs' URL Rating (UR) and Semrush's Page Score, though exact values differ due to differing link indexes and algorithms. From an ROI perspective, PA is used to evaluate the potential revenue impact of link building campaigns targeting specific pages, to identify high-PA pages that could be internally linked to boost lower-PA pages, to benchmark content performance against competitors, and to estimate the ranking potential of newly created pages. The PA of a page correlates with its ranking position, though Google uses hundreds of additional signals not captured by PA. A page with PA 40 competing against pages with PA 50 to 60 will typically struggle to reach page 1, suggesting either additional link building is needed or keyword targeting should shift to lower-competition terms. Calculating the ROI of PA improvement requires estimating the traffic and revenue impact of moving from one ranking position to another for target keywords.
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Formula
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Page Authority: Logarithmic 1-100 scale (Moz proprietary); PA ≈ log-scaled composite of: Number and quality of external links to the page, linking domain authority, link anchor text relevance, internal link equity passed from other site pages, page-level spam score; PA prediction: Higher PA correlates with higher SERP rankings but is not a Google metric; Link equity flow: PA of linking page / Number of outbound links × Follow status; Improving PA: Build quality backlinks, optimize internal linking, ensure crawlability; Note: PA is relative — as the web grows, scores shift; compare within competitive setVariable Legend
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| Symbol | Name | Unit | Description |
|---|---|---|---|
| PA Score | Moz Page Authority | — | Moz Page Authority score 1 to 100 for specific URL |
| Internal Links | Volume and PA | — | Volume and PA of internal pages linking to this page |
| Domain Authority | The DA | — | The DA of the domain hosting this page (baseline floor for PA) |
How to Page Authority Calculator
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- 1Gather the required input values: Moz Page Authority, Number and quality, Volume and PA, The DA.
- 2Apply the core formula: Page Authority (Score 1-100) = f(External Links × Link Quality × Internal Link Equity × Domain Authority).
- 3Compute intermediate values such as Link Equity Flow if applicable.
- 4Verify that all units are consistent before combining terms.
- 5Calculate the final result and review it for reasonableness.
- 6Check whether any special cases or boundary conditions apply to your inputs.
- 7Interpret the result in context and compare with reference values if available.
Worked Examples
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Applying the Page Authority Calc formula with these inputs yields: PA improvement from 22 to 34 could unlock $25,920/yr revenue. Link building cost $3,000 = 764% ROI.. This demonstrates a typical page authority scenario where the calculator transforms raw parameters into a meaningful quantitative result for decision-making.
Applying the Page Authority Calc formula with these inputs yields: $7,560/yr incremental revenue from internal linking alone — zero cost beyond audit time.. This demonstrates a typical page authority scenario where the calculator transforms raw parameters into a meaningful quantitative result for decision-making.
Applying the Page Authority Calc formula with these inputs yields: PA gap analysis prevents wasted effort on unwinnable keywords. Redirect to achievable ranking targets.. This demonstrates a typical page authority scenario where the calculator transforms raw parameters into a meaningful quantitative result for decision-making.
Applying the Page Authority Calc formula with these inputs yields: $4,320/yr incremental revenue from single link. $500 cost = 764% ROI. Positive acquisition decision.. This demonstrates a typical page authority scenario where the calculator transforms raw parameters into a meaningful quantitative result for decision-making.
Real-World Applications
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Identifying which pages to prioritize for link building campaigns, representing an important application area for the Page Authority Calc in professional and analytical contexts where accurate page authority calculations directly support informed decision-making, strategic planning, and performance optimization
Evaluating the potential traffic value of acquiring links from specific publishers, representing an important application area for the Page Authority Calc in professional and analytical contexts where accurate page authority calculations directly support informed decision-making, strategic planning, and performance optimization
Diagnosing why certain pages are not ranking despite good content, representing an important application area for the Page Authority Calc in professional and analytical contexts where accurate page authority calculations directly support informed decision-making, strategic planning, and performance optimization
Benchmarking page-level authority against competitors in SERP analysis, representing an important application area for the Page Authority Calc in professional and analytical contexts where accurate page authority calculations directly support informed decision-making, strategic planning, and performance optimization
Measuring internal linking effectiveness on page authority over time, representing an important application area for the Page Authority Calc in professional and analytical contexts where accurate page authority calculations directly support informed decision-making, strategic planning, and performance optimization
Special Cases
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Newly published pages: start with very low PA regardless of DA — requires link building specifically to that URL.
In the Page Authority Calc, this scenario requires additional caution when interpreting page authority results. The standard formula may not fully account for all factors present in this edge case, and supplementary analysis or expert consultation may be warranted. Professional best practice involves documenting assumptions, running sensitivity analyses, and cross-referencing results with alternative methods when page authority calculations fall into non-standard territory.
Redirected pages: PA from old URL transfers partially (estimated 85 to 99%) to new URL via 301 redirect.
In the Page Authority Calc, this scenario requires additional caution when interpreting page authority results. The standard formula may not fully account for all factors present in this edge case, and supplementary analysis or expert consultation may be warranted. Professional best practice involves documenting assumptions, running sensitivity analyses, and cross-referencing results with alternative methods when page authority calculations fall into non-standard territory.
Paginated pages: avoid building links to page 2+ of paginated series; consolidate link equity to page 1 or canonical.
In the Page Authority Calc, this scenario requires additional caution when interpreting page authority results. The standard formula may not fully account for all factors present in this edge case, and supplementary analysis or expert consultation may be warranted. Professional best practice involves documenting assumptions, running sensitivity analyses, and cross-referencing results with alternative methods when page authority calculations fall into non-standard territory.
Page Authority Calc reference data
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| PA Range | Interpretation | Typical Link Profile | Competitive Landscape |
|---|---|---|---|
| 1 - 10 | Very weak | 0 - 5 backlinks | Easy to outrank |
| 11 - 20 | Weak | 5 - 30 backlinks | Low competition niches |
| 21 - 35 | Moderate | 30 - 200 backlinks | Average competitive |
| 36 - 50 | Good | 200 - 2,000 backlinks | Competitive SERPs |
| 51 - 65 | Strong | 2,000 - 20,000 backlinks | High competition |
| 66 - 80 | Very strong | 20,000+ quality backlinks | Authority sites only |
| 81 - 100 | Exceptional | Millions of backlinks | Wikipedia/BBC level |
Frequently Asked Questions
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What is Page Authority and how is it calculated?
Page Authority (PA) is a logarithmic score that predicts how likely a specific webpage is to rank in search engine results pages (SERPs), on a scale of 1 to 100. It is calculated based on factors such as the number and quality of linking root domains, the number of total linking domains, and the page's internal and external link profile. For example, a webpage with 10 high-quality linking root domains and a strong internal link profile may have a PA score of 50, indicating moderate ranking strength.
How do I use Page Authority in my SEO strategy?
Page Authority can be used to evaluate the ranking strength of individual webpages and identify areas for improvement. By analyzing the PA scores of your website's pages, you can determine which pages are most likely to rank well and prioritize optimization efforts accordingly. For instance, if you have a webpage with a PA score of 20, you may want to focus on building high-quality backlinks to that page to increase its ranking potential.
What are typical Page Authority score ranges for different types of websites?
Page Authority scores can vary widely depending on the type of website and its level of optimization. For example, newly created websites may have PA scores ranging from 1 to 10, while established websites with strong link profiles may have scores ranging from 50 to 90. On average, a well-optimized webpage may have a PA score of around 40 to 60, indicating moderate to strong ranking potential.
What are some common mistakes to avoid when interpreting Page Authority scores?
One common mistake is to focus too heavily on PA scores as the sole indicator of a webpage's ranking potential. It's also important to consider other factors such as content quality, keyword relevance, and technical optimization. Additionally, PA scores can fluctuate over time due to changes in the linking landscape, so it's essential to regularly monitor and adjust your SEO strategy accordingly. For example, a sudden drop in PA score may indicate a loss of high-quality backlinks, which can be addressed through targeted link building efforts.
Can you provide a real-world example of how Page Authority has been used to improve search engine rankings?
For example, a company like Amazon may have a webpage with a PA score of 80 for its product category page, indicating strong ranking potential. By analyzing the linking profile of this page, Amazon may identify opportunities to build additional high-quality backlinks from relevant sources, such as product review websites or industry blogs. By doing so, Amazon can increase the PA score of this page to 90, resulting in improved search engine rankings and increased organic traffic. This can lead to a significant increase in sales and revenue, demonstrating the practical value of Page Authority in SEO strategy.
Common Mistakes to Avoid
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- !Treating PA as a Google ranking factor — it is a predictor, not a direct signal
- !Comparing PA scores from different tools (Moz PA vs. Ahrefs UR) without noting the source
- !Focusing on PA at the expense of content quality and user experience signals
- !Expecting immediate PA improvement after acquiring new links — crawl and update lag of 4 to 8 weeks
- !Building links to the homepage only — individual product and content pages need direct links to improve their PA
- !Ignoring internal link opportunities while spending heavily on external link acquisition
Pro Tip
Use Moz's free Link Explorer or Ahrefs' free PA checker to audit your top revenue-generating pages. If their PA is significantly below competitors ranking above them, prioritize link building to those specific pages for maximum SEO revenue impact.
Did you know?
Moz introduced Domain Authority and Page Authority in 2004 to solve the problem of measuring link equity. These metrics have since become the de facto standard for the SEO industry — used by millions of marketers worldwide despite being third-party, non-Google metrics.
Regional Guides
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References
- ›Moz — Page Authority Definition and Methodology
- ›Moz — Page Authority vs Domain Authority
- ›Ahrefs — URL Rating Documentation
- ›Search Engine Journal — How Page Authority Affects Rankings
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