Internal Link Depth & PageRank Flow Modeller
Interactive calculator to model internal crawl depth distribution, calculate PageRank decay across click tiers, and estimate crawl budget waste.
Internal Link Depth & PageRank Flow Modeler
Simulates link equity distribution, crawl depth tiers (Tier 0 Homepage through Tier 4+ Long-tail), PageRank damping decay (d=0.85), and crawl budget waste across enterprise site taxonomies.
Internal Link Depth & PageRank Flow Modeller Configurator
4-Tier Enterprise Website Architecture — PageRank Flow & Depth Model
PageRank flow distribution and crawl depth analysis across a 261-page hierarchical website architecture.
1 Input Parameters & Assumptions
| Parameter | Value | Context & Provenance |
|---|---|---|
| Depth 0 (Homepage) | 1 page URLs | Root homepage tier |
| Depth 1 (Top Hubs / Categories) | 10 pages URLs | Primary navigational categories and pillar pages |
| Depth 2 (Subcategories) | 50 pages URLs | Mid-level topic clusters and subcategory hubs |
| Depth 3 (Articles & Products) | 200 pages URLs | Leaf content, resources, and transactional product pages |
| Damping Factor | 0.85 Damping (d) | Standard PageRank link transition probability |
| Target Max Click Depth | 3 Clicks | Maximum recommended click distance from homepage |
2 Explicit Mathematical Formula
PageRank Decay: PR_tier = DampingFactor^Depth = 0.85^Depth
Depth 0 (Home: 1 page) = 0.85^0 = 1.0000 (Tier PR: 1.00)
Depth 1 (Hubs: 10 pages) = 0.85^1 = 0.8500 (Tier PR: 8.50)
Depth 2 (Subcategories: 50 pages) = 0.85^2 = 0.7225 (Tier PR: 36.13)
Depth 3 (Articles: 200 pages) = 0.85^3 = 0.6141 (Tier PR: 122.83)
Total Active Pages = 1 + 10 + 50 + 200 = 261 pages
Crawl Depth Score = (Pages within Target Max Depth 3 / Total Pages) × 100 = (261 / 261) × 100 = 100.0%
Crawl Budget Waste = 0.0% (0 pages at Depth 4+)3 Computed Output Metrics
| Computed Metric | Result | Interpretation & Threshold |
|---|---|---|
| Total Indexed URLs | 261 Pages | Total addressable site architecture page volume |
| Crawl Depth Score | 100.0% Architecture Health | 100% of pages reachable within 3 clicks of root homepage |
| Crawl Budget Waste | 0.0% Waste Ratio | Zero URLs stranded in deep crawl tiers (Depth 4+) |
| Architecture Rating | EXCELLENT Rating Tier | Optimal crawl distribution ensuring efficient Googlebot re-indexing |
Internal Link Depth & PageRank Flow Modeller — Scope & Limitations
Explicit operational boundaries and constraints defining target use cases and out-of-scope scenarios.
Built For (Target Use Cases)
- Modelling internal PageRank decay across click-depth tiers with a selectable damping factor from 0.75 to 0.90.
- Estimating crawl budget waste from manually entered page counts at each depth level.
- Comparing site architectures against a fixed 3-click target depth benchmark.
Not Built For (Limitations & Out-of-Scope)
- Reading live crawl data; all page counts and depths must be entered manually.
- Modelling backlink-driven external PageRank inflow or link equity from off-site sources.
- Auditing individual URLs, orphan pages, or actual click paths on a real site.
Operational Assumptions & Defaults
- Damping factor defaults to 0.85, with 0.75 and 0.90 offered as the only alternatives.
- Target maximum click depth is fixed at 3 and cannot be changed by the user.
- Page counts per tier and orphan count are user-supplied estimates, not crawled data.
Internal Link Depth & PageRank Flow Modeller
Technical SEO & ArchitectureSimulate internal PageRank distribution decay across click tiers using the 0.85 damping factor model and calculate crawl budget waste percentage on deep or orphaned URLs.
Site Hierarchy & URL Distribution
Crawl Architecture & Equity Summary
PageRank Flow & Tier Distribution
Architecture Recommendations
- Internal link architecture is optimal. All pages sit within the 3-click crawling threshold with zero orphaned URLs.
Apply Internal Link Architecture Plan
Export the optimized link distribution model to CSV and implement recommended pagination, related links, and breadcrumbs to pull key revenue pages into Tier 1–3.
Why Crawl Depth Governs Indexation Frequency
Search engine crawlers allocate finite resources to each domain. Pages located 4 or more clicks from the home page receive exponential reductions in internal link equity and are crawled less frequently. Keeping key content within 3 clicks ensures consistent indexation.
Implementation Code & Script
Calculates exponential PageRank decay per crawl tier based on standard 0.85 damping factor.
export function calculateTierPageRank(depth: number, damping: number = 0.85): number {
return Math.pow(damping, Math.max(0, depth));
}
export function evaluateCrawlBudgetHealth(pagesAtDepth4Plus: number, totalPages: number): number {
if (totalPages === 0) return 0;
return Number(((pagesAtDepth4Plus / totalPages) * 100).toFixed(2));
}Crawl Depth & Orphan Page QA
Validate site crawl depth in Screaming Frog or Sitebulb to confirm 90%+ of indexable URLs are accessible within 3 clicks.
Pre-Production Verification Checklist
Verify in site crawl reports that critical revenue URLs do not exceed crawl depth 3.
Reconcile XML sitemap against internal crawl to identify and eliminate orphan URLs.
Ensure every subcategory and product page contains structured breadcrumbs linking back up the hierarchy.
Terminal Diagnostic & Debug Commands
Runs headless crawl and outputs crawl_overview.csv with click depth distribution table.
screamingfrogseospider --crawl https://example.com --headless --export-format csv --output-folder ./crawl-dataFailure Remediation & Troubleshooting
Cause: Pagination is implemented with JavaScript infinite scroll without static HTML fallback links.
Fix: Deploy server-rendered HTML <a href="?page=2"> pagination links with rel="next" and breadcrumbs.
Cause: Faceted search generates millions of parameter combinations without rel="nofollow" or robots.txt blocking.
Fix: Add canonical tags pointing to root category and disallow deep query strings in robots.txt.
How to cite and attribute this tool
MIT LicenceThis resource is free, open and un-gated under the MIT Open Source Licence. You are encouraged to use, integrate and cite it with attribution:
@misc{geraghty_internal_link_depth_modeler,
author = {Geraghty, Gordon},
title = {Internal Link Depth & PageRank Flow Modeller},
year = {2026},
url = {https://gordongeraghty.com/resources/technical-seo/internal-link-depth-modeler},
note = {Head of Performance Media, Empire Amplify}
}Changelog & Version History
v1.0.0Initial release of link depth and PageRank flow modeller.
Strategic Takeaway & Operational Guidelines
With 100% of URLs accessible within 3 clicks, internal link equity flows cleanly without dilution. Maintaining flat crawl hierarchy ensures fast search engine indexation of newly published content without requiring excessive XML sitemap pinging.