About Angle Finder

Why Angle Finder Exists

Angle Finder was built to address a widespread frustration with online measurement and calculation utilities: excessive bloat, invasive paywalls, deceptive mobile app ads, and heavy third-party framework overhead. When working in a woodshop, on a construction job site, or in a classroom, users need an instrument that loads immediately, operates reliably, and calculates without distractions.

The mission of Angle Finder is straightforward: provide free, dependable, mathematically rigorous angle measurement and calculation instruments on the open web.

Editorial & Calculation Methodology

Every calculator and reference guide published on Angle Finder adheres to strict editorial and computational principles:

• Pure Analytical Mathematics: Geometric algorithms and unit conversions are derived directly from closed-form planar trigonometry (such as the Law of Sines, Law of Cosines, and Pythagorean theorem) rather than approximations.
• Primary Source Building Codes: Building and trade guidelines cite specific sections of published standard codes (such as the International Residential Code for residential stairs and roof underlayment, and the International Building Code for commercial egress stairs). Where limits vary locally, we explicitly note that local municipal codes supersede model codes.
• Comfort vs. Code Separation: Ergonomic guidelines (such as the historical 30°–37° stair angle comfort recommendation or the 1675 Blondel stride formula) are explicitly labeled as comfort guidelines rather than legal building codes.

Corrections & Accuracy Policy

We are committed to absolute accuracy across our math implementations, trade tables, and educational explanations. If you identify a computational bug, a typographical error, or an outdated code reference:

1. Please email details of the discrepancy to contact@anglefinderonline.com with the subject line "Correction Request".
2. Include the specific page URL, the input values tested, the expected result according to published code or mathematical proof, and citation of the standard.
3. Our technical maintainers review reported discrepancies promptly and publish documented updates in our changelog.

Sources & Reference Standards

Our calculators and reference materials cite and adhere to established architectural, trade, and engineering standards:

• International Code Council (ICC) - International Residential Code (IRC): Section R311.7.5 (residential stair risers and treads) and Section R905.2.2 / Table R905.1.1(2) (roof pitch underlayment and slope thresholds).
• International Code Council (ICC) - International Building Code (IBC): Section 1011.5.2 (commercial stairway riser and tread limits).
• Blondel's Stride Rule: Nicolas-François Blondel, Cours d'architecture (1675), establishing the classical human stride equation: 2 × Rise + Tread = 24" to 25" (60 to 64 cm).
• U.S. Access Board - Americans with Disabilities Act (ADA): Standards for Accessible Design, Section 405 (Ramps, specifying a maximum slope of 1:12 / 8.33% / 4.76°).
• Euclidean Geometry & Trigonometry: Standard planar trigonometric identities for vector dot products, right-triangle geometry, and oblique triangle solutions (Law of Sines and Law of Cosines).

Privacy Approach: 100% Local In-Browser Processing

Your privacy is an architectural priority. When you open a photo, blueprint, or camera capture in our measurement tools:

• Zero Server Uploads: Images are decoded and rendered entirely inside your device’s local browser memory using HTML5 Canvas and FileReader APIs. No images or files are ever transmitted to our server or any third party.
• Local Sensor Execution: Motion and orientation data accessed by the Phone Angle Finder is read in real-time by browser event listeners and never logged or stored.
• No Mandatory Account or Registration: Every tool is immediately accessible without creating an account or providing personal details.