Verification

A calculator that is merely plausible is a liability. This page records, for every calculator on the site, what its results are checked against and when that was last done. It is published rather than kept internally, because an engineer putting a number into a submission is entitled to know how that number was verified.

A calculator cannot be marked verified unless it reproduces at least three independent worked examples, and the check runs in continuous integration — the badge below is generated from the test suite, not maintained by hand.

2 of 6 calculators verified

CalculatorBasisChecked againstExamplesLast verifiedStatus
Beam Bending Moment, Shear and Deflection CalculatorElastic beam theory — no design code governs itClosed-form solutions, cross-checked against hand-worked round numbers62026-09-13verified
Concrete Beam Deflection Checker—No source supplied0—unverified
Concrete Test Cylinder Calculator—No source supplied0—unverified
Concrete Volume CalculatorGeometry — no design code governs itClosed-form arithmetic, derived independently in the test suite52026-09-13verified
SPT Bearing Capacity Calculator—No source supplied0—unverified
Steel Beam Size Calculator—No source supplied0—unverified

What the statuses mean

Verified
Reproduces at least three independent worked examples to a stated tolerance, checked on every commit. Where the basis is a design code, the source is a published example; where it is geometry or elastic theory, the expected values are derived from first principles in the test rather than copied from a table.
Unverified
The method is implemented and documented, but no worked example has been supplied to check it against. These cannot be published, and the badge appears on the calculator page itself, not only here.
Superseded
Replaced by a newer calculator or code edition, kept so historical reports still reproduce.

Tolerances

Stated per test and justified. Typically 0.5–1%, tighter where the source is exact arithmetic rather than a rounded published value. Where a published example and this engine disagree, the discrepancy is documented rather than tuned away — including the cases where the published example itself contains an arithmetic slip.