API 653 Annex B
Differential Settlement Calculator
B.3.2.1 Cosine Curve & B.3.2.2 Arc Methods
Mobile-First
Built for phone use in the field — large touch targets, numeric keyboards
Transparent Math
Every intermediate calculation step shown explicitly so you can verify against the standard
Both Methods
B.3.2.1 (cosine curve, Marr) and B.3.2.2 (arc method, Andreani-Carr) with automatic R² selection
Based on API 653, 5th Edition, Annex B
Formulas verified against published worked examples
All results must be verified by a qualified API 653 Authorized Inspector