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.

P-M Interaction and Moment–Curvature for Circular or Rectangular RC Member

Performs axial force–moment (P-M) interaction and moment–curvature analyses for members of circular and rectangular cross-section. Complies with AASHTO LRFD. Uses the Mander model for the confined and unconfined concrete stress–strain relations

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.

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.

Base Plate — Biaxial Analysis

Performs biaxial analysis of general-shaped base plates under combined axial load, biaxial moment, shear, and torsion. Supports rectangular, circular, polygon, and custom plate shapes with openings.

Beam Dynamic Analysis

Performs dynamic analysis of beams, including eigenvalue and time-history analysis of a moving vehicle load. Reports natural frequencies and mode shapes along with static and dynamic force effects, and dynamic amplification factors. The app supports multiple spans, variable linear and concentrated loads, and custom vehicle configurations.

Beam On Elastic Foundation

Interactive analysis of a beam on a Winkler elastic foundation with arbitrary point and linear distributed loads. Performs non-linear analysis when a compression-only subgrade option is selected.

Friction and Seating Losses in Prestressed Tendons

It's a spin off of a popular spreadsheet PSLoss. Build a tendon profile from parabolic and straight segments and calculate elongations and stresses along the tendon. Handles stressing at one or both ends, using AASHTO or Eurocode equations.