Loadsheaf: free online structural load and combination tool

Loadsheaf is a free, browser-based ledger for structural load cases. Enter the parameters from your governing code and project: air density, design speed and pressure coefficients for wind; ground snow pressure and roof factors for snow; nominal pressure, tributary area and your reduction parameters for live load; or a seismic coefficient, distribution exponent and level weights for an equivalent lateral force distribution. Loadsheaf shows each step of the calculation, from dynamic pressure to the force at every level.

Map each generated force to the responses you track through influence coefficients from your own analysis, list the combinations you need with signed factors, and read the envelope with the governing combination for every response. No code factors are built in: every coefficient is yours and is recorded with its source. Calculations run in a worker in your browser, the reference checks run in the Verify view, and projects are saved as open JSON files.

What Loadsheaf can do

Wind dynamic pressure, net pressure and surface force with signed coefficients
Uniform roof snow from ground snow pressure and your factors
Area-based live-load reduction with explicit eligibility, threshold and lower bound
Seismic base shear, level forces with a weight × height^k distribution, story shears and overturning
Influence matrices, signed load combinations and envelopes with governing combinations
JSON projects, CSV results, SVG and PNG charts and a printable report

How we verify Loadsheaf

Loadsheaf is checked against 99 independent reference cases. Where a reference answer exists you can run every check yourself on the Verify page, and the Loadsheaf user guide documents every feature and limitation.

The Verify tab runs the same reference catalogue as the automated tests, in your browser: 119 ready cases (88 verification, 31 validation) and 2 pending a legitimate source. Each case states what is checked, the independent reference, the computed value, the difference, the tolerance and PASS or FAIL. Run all checks produces a summary badge and a printable report.

Loadsheaf is part of Open Tools, the free engineering tools that run in your browser.

Professional use. Results are for education and preliminary design. They must be checked by a qualified professional, and they are not a substitute for code-compliant design or licensed engineering judgement.