What the dated QA record means
Each published calculator has automated checks for an Imperial/Metric measurement round trip and finite, equivalent-project results. Additional known-answer tests cover selected formulas, including area pricing, slab volume and paint openings. The formula registry records the tested version and date. Source fingerprints and tests must pass before deployment. These checks are not an independent engineering review or proof that every possible input is correct.
Who tests a formula
Feroz Sheikh writes the public calculators and runs their internal QA. Internal testing means: the formula ID, version, units, worked example and limitations were checked. Independent third-party engineering review is not claimed. Construclytic is not a registered engineering or contracting firm.
Formula-first, not black-box arithmetic
Each published calculator identifies a formula ID and version, keeps the inputs visible and shows the calculation trail. Calculator arithmetic is deterministic TypeScript, not LLM-generated output. Some editorial explanations were drafted with AI assistance; every number on a result still comes from the published deterministic formula. If a correction ships, the version changes and the changelog says so.
Worked example — 20 × 12 ft slab, 4 in thick
A rectangle 20 ft by 12 ft, 4 in thick, with 8% waste: net volume is 2.96 yd³. Ready-mix order quantity rounds to 3.25 yd³ on a 0.25 yd³ step, and 40/50/60/80 lb bag counts stay on the sheet. Formula CONC-SLAB-001 version 1.2.0. This is a planning quantity — not a mix design, not a structural size, and not a supplier quote.
Allowance and purchase rounding stay visible
Waste, product coverage, packaging and order increments are shown as planning inputs. A mathematical quantity is not represented as a final supplier order without the required field and product checks.
Cost components are separate
Material quantity does not hide labour, equipment, delivery, contingency, markup, discount, tax, exclusions or final commercial terms. These remain explicit estimate decisions. Costs use the rate you enter. Construclytic does not fetch live supplier prices.
Why these pages exist
They exist so a contractor or planner can inspect the takeoff, carry it into an estimate, and send a client letter without a black-box total. They are not published to manufacture search results. Thin keyword copies of the same calculator are not the product.
Planning boundary
Tools assist planning. They do not determine structural design, code compliance, product compatibility, supplier availability, guaranteed pricing or final scope.
