Beam Calculator
Multi-span beam analysis by direct stiffness: reactions, shear and moment diagrams, deflection against L/360 and L/240. Cantilevers and fixed ends supported.
NDS 2018 · AISC 360-22 · ASCE 7-22 combinations
Open the calculator →Wood Beam
Sawn lumber by species, grade and size, built-up plies and the repetitive member factor, with the NDS 2018 ASD bending and shear check.
NDS 2018
Open the calculator →Steel Beam
W shapes from the AISC database; step to the next size up by Zx or Ix, across all depths or inside one family. ASD or LRFD, unbraced length, flexure and shear.
AISC 360-22
Open the calculator →Wood Joist
Floor and roof joists at an on-center spacing: dead and live load in psf, line loads crossing the joists, the repetitive member factor, and the 2,000 lb concentrated load.
NDS 2018 · IBC 2021
Open the calculator →Concrete Beam
Rectangular concrete beams: tension bars and stirrups sized from the LRFD envelope, Ec from f'c, gross or cracked stiffness, self-weight, diagrams and deflection.
ACI 318-19
Open the calculator →Spread Footing
Concentric square footing: soil bearing, one-way shear, two-way punching shear and flexural steel with bar options. Loads by case get the governing combination named.
ACI 318-19 · ASCE 7-22
Open the calculator →Load Combinations
Every LRFD and ASD combination for your dead, live, roof, snow, rain, wind and seismic load effects, with the governing maximum and minimum for each method.
ASCE 7-22 §2.3, §2.4
Open the calculator →Snow Load
Flat-roof snow pf, the §7.3.4 minimum pm as its own load case, slope factor Cs, and unbalanced gable snow. Every factor cites its table.
ASCE 7-22 Ch 7
Open the calculator →Wind MWFRS
Directional Procedure: qz velocity-pressure profile, wall and roof pressures with both internal-pressure cases, story forces and base shear.
ASCE 7-22 Ch 26, 27
Open the calculator →Wind Components and Cladding
Design pressures on wall and roof zones for windows, doors, siding, sheathing and roofing, from the effective wind area and both internal-pressure cases.
ASCE 7-22 Ch 26, 30
Open the calculator →Retaining Wall
Cantilever retaining wall: overturning, sliding, bearing, stem and footing design. Part of the desktop program, which is in active build.
IBC 2021 §1807.2 · ACI 318-19
Read the stability walkthrough →How these work
One engine, two products.
The desktop engine, in your browser
The calculation modules behind the desktop app are pure calculation: no file access, no database, no user interface. They compile to WebAssembly unchanged, so a free calculator here is the same code the desktop calc package comes from. A fix lands in both at once.
The engine runs on your machine. The server only hands over a static file, and your inputs never leave the page unless you sign in and save a calc.
What the free tools do not do
What stays in the paid plans and the desktop program.
Limited saving
A free sign-in saves 5 calcs per tool. Basic saves 200 per tool; project files, revisions and templates are desktop features.
No sealed calc package
Printing carries a StructuralClaw watermark. The reviewer-ready PDF with the code citation on every value is the desktop deliverable.
Fixed code edition
ASCE 7-22 and current ACI, AISC and NDS only, with default combinations. Edition switching and custom combinations are desktop features.