Spreadsheets for Structural Engineers

Online Calculators

These browser-based calculators run entirely in your browser — no download, no license, no Excel required. They share the same algorithms and design-code references as our spreadsheet tools and are freely available to all visitors.

RC Column P-M Interaction

Generates the axial force–moment interaction diagram for circular reinforced concrete columns using strain compatibility. Computes nominal and factored capacity envelopes per AASHTO LRFD 10th Edition and plots user-supplied load cases against the diagram.

Free

BoltGroup — Eccentric Shear

Calculates shear resistance of the eccentrically loaded bolt group using the elastic and instantaneous center of rotation methods per AISC LRFD. Supports standard and irregular bolt layouts with a live graphical display.

Free

Influence Lines — Continuous Beam

Computes moment and shear influence lines at any section of a continuous beam with up to 8 spans and variable EI. Slides a user-defined truck (default HS20) in both directions and combines with lane load to generate moment and shear force envelopes along the full beam length.

Free