Summary: BuildQuantities separates measured geometry from product-dependent ordering assumptions. A calculator reaches the public launch gate after its formula, units, examples, edge cases, sources, review ownership, and rendered behavior have been checked.
Calculation workflow
- Define the user task, audience, output, and practical boundary.
- Write the formula and variable definitions before building the interface.
- Identify the unit system, exact conversion factors, input constraints, material state, and rounding rule.
- Map each external claim or constant to an appropriate source.
- Test normal examples, boundary values, invalid inputs, unit switches, and independent hand calculations.
- Record editorial and technical review ownership, then run the site build and rendered-page checks.
Source hierarchy
| Question | Preferred evidence | Use in a calculator |
|---|---|---|
| Exact unit conversion | National metrology authority such as NIST | Conversion constants and unit definitions |
| Code, safety, or regulatory rule | Applicable government or issuing authority | Scope boundary and direct source link |
| Product yield, density, package size, or selling unit | Selected manufacturer or supplier documentation | User-controlled product input or clearly labelled product value |
| Project dimensions and required layer | Field measurements, drawings, and specifications | Geometry and project-specific assumptions |
| Search intent and missing user questions | Live search results and competitor review | Page brief and usability improvements; technical claims use primary or project sources |
Calculator specification record
Each tool needs a written specification that can be reviewed separately from its interface.
| Field | Required record |
|---|---|
| Purpose and boundary | The task solved, intended audience, and decisions left to project documents or qualified people |
| Variables | Name, meaning, accepted units, valid range, default state, and whether the value is required |
| Formula | Symbolic expression, calculation order, conversions, and result units |
| Material state | In-place, loose, delivered, settled, compacted, wet, dry, or another stated condition |
| Rounding | Internal precision, displayed precision, and any whole-package or whole-trip rule |
| Sources | Claim or constant, issuing body, URL, scope, and date checked |
| Fixtures | Expected results for normal, boundary, invalid, and unit-conversion cases |
Geometry and purchasing remain separate
The first result describes measured geometry. Density, package yield, compaction or settlement information, material allowance, minimum order, delivery increment, and price belong to later planning stages.
Keeping these stages separate shows which result came from measurement and which value came from a project document, supplier, or user-selected assumption.
Units and conversion control
Inputs use one compatible unit system during a calculation. A unit switch converts populated values with stated factors and clears any result that could otherwise look current. The NIST Guide to the SI conversion factors supplies the project’s base customary and metric relationships.
Labels stay visible beside inputs and results. Symbols such as ft³, yd³, m³, lb, short ton, kg, and metric tonne remain distinct.
Rounding method
Calculation logic retains full available precision through intermediate steps. Display rounding occurs at the stated final precision. Package counts and trip counts may round up when the task requires whole units, while the unrounded planning result remains visible.
Supplier rounding is recorded after the measured quantity and any documented allowance. The measured geometric result remains unchanged.
Test matrix
| Test class | Example check |
|---|---|
| Known fixture | Independent hand calculation matches the displayed value |
| Boundary | Minimum valid positive value, large valid value, and exact unit boundary |
| Invalid input | Blank, zero, negative, nonnumeric, or impossible combination produces a specific visible message |
| Unit switch | Populated inputs convert once, labels change, and stale results clear |
| Rounding | Intermediate precision and final display follow the specification |
| Rendered behavior | Keyboard use, labels, alert or live-result region, desktop, mobile, links, and console |
Review and publication states
“Editorial review complete” means the page structure, wording, source presentation, internal links, and originality checks have passed the development review. “Technical reviewer pending” means the page stays outside the public index until a qualified named reviewer accepts the technical scope assigned to that page.
A working calculator, a passing build, and an editorial review each answer different questions. The launch gate requires all applicable checks and truthful ownership.
Professional and project boundary
BuildQuantities supports quantity planning. Project drawings, specifications, codes, safety requirements, supplier data, site conditions, and the responsible qualified people control design, compliance, product acceptance, and safe execution.
Updates and corrections
A material change to a formula, source, assumption, test fixture, or limitation triggers a new review. Confirmed errors are corrected, related tests rerun, the review date updated, and a material correction explained on the affected page. Use the corrections process to prepare a report.
Guidance used for this policy
- Google Search Central: creating helpful, reliable, people-first content: purpose, sourcing, authorship, and reader value.
- Google Search Central: guidance on generative AI content: accuracy, quality, relevance, and added value.
- NIST Guide to the SI, Appendix B: unit conversion factors.