A is a powerful, accessible tool for engineers from preliminary assessment to final design. While you may not find a single “perfect link” that fits every code and project need, many reputable spreadsheets are available through professional societies, software vendors, or public domain repositories.
(XLS/XLSX) from engineering repositories and community forums. These spreadsheets typically automate structural analysis using the moment distribution method and are built around standard codes like AASHTO LRFD Top Download Links for Box Culvert XLS The Engineering Community : Offers a specialized Structural Design of Single Cell Box Culvert Spreadsheet box culvert design calculations xls link