Page Authority Predictor
Predict a page's authority score using backlink profile, referring domains, domain authority, content quality, and technical SEO health. Useful when prioritizing link-building and on-page optimization efforts.
About this calculator
Page authority is a logarithmic metric — meaning early backlinks add far more value than additional links to an already well-linked page. This predictor models that with: PA = min(100, (ln(totalBacklinks + 1) × 8) + (√uniqueDomains × 6) + (domainAuthority × 0.3) + (contentQuality × 15) + (technicalScore × 12)). The natural log of backlinks captures diminishing returns, while the square root of unique referring domains rewards link diversity without over-weighting bulk links from one source. Domain authority contributes a baseline of up to 30 points. Content quality (scored 0–5 or 0–10 depending on your rubric) and technical SEO score round out the on-page and structural contributions. The result is capped at 100, mirroring the Moz PA scale convention.
How to use
Suppose a page has 200 backlinks, 40 unique domains, a domain authority of 50, a content quality score of 7, and a technical SEO score of 8. Backlinks: ln(201) × 8 = 5.303 × 8 = 42.42. Domains: √40 × 6 = 6.32 × 6 = 37.95. DA: 50 × 0.3 = 15. Content: 7 × 15 = 105 → but total is capped at 100. Combined raw = 42.42 + 37.95 + 15 + 105 + 96 = 296.37, so output = min(100, 296.37) = 100. Try smaller inputs — e.g., 20 backlinks, 10 domains, DA 30, content 3, technical 4 → ln(21)×8 + √10×6 + 9 + 45 + 48 = 24.1 + 18.97 + 9 + 45 + 48 = 145.07 → capped at 100.
Frequently asked questions
What is page authority and how is it different from domain authority?
Page Authority (PA) scores the ranking strength of a single URL, while Domain Authority (DA) measures the overall strength of an entire website. A high-DA site can have individual pages with lower PA if those pages lack backlinks or quality content. Both metrics were popularized by Moz and use a 1–100 logarithmic scale. When building links, targeting pages that need PA boosts is more surgical than focusing solely on domain-level metrics.
How many backlinks do I need to increase my page authority?
Because the formula uses a natural logarithm, the first 10–50 backlinks drive the largest PA increases, with returns diminishing sharply beyond 500. Equally important is link diversity — backlinks from many unique domains outweigh many links from a single source, as reflected by the square-root term for referring domains. Focus on earning links from relevant, authoritative sites rather than accumulating volume from low-quality sources.
Why does technical SEO score affect page authority predictions?
Technical issues like slow load times, broken links, missing canonical tags, or poor mobile usability directly reduce a page's ability to be crawled, indexed, and ranked — regardless of its backlink profile. Search engines discount pages with technical problems when assessing authority. Fixing Core Web Vitals, eliminating crawl errors, and ensuring proper schema markup can meaningfully lift your effective page authority without any new link building.