Methodology

1. Exact math

Unit conversions, area, volume and geometry formulas are implemented in reusable TypeScript calculation libraries. Intermediate calculations keep full precision. User-facing values are rounded for readability only after the underlying result has been calculated.

Where a purchase must be made in whole units—such as cartons, sheets, bags or panels—the whole-unit result is rounded upward at the final purchase step.

2. Variable inputs stay visible

We do not present one product-specific or regional value as if it were universal. Examples include gravel density, sod pallet coverage, grass-seed application rate, flooring carton coverage, fence spacing and paver base depth. Depending on the tool, those values are entered by the user, offered as source-labeled references or omitted as defaults.

3. Source policy

When a convenience preset is published, the source and verification policy are documented on Sources & Data. Product labels, supplier specifications, project plans and applicable local requirements take precedence over general reference values.

4. Testing and quality control

Calculation libraries are covered by direct automated test vectors, including expected results and invalid-input cases. Static quality checks also verify calculator routes, internal links, form-label targets, indexing safeguards and selected no-hidden-default policies. A full framework build and rendered-browser QA are separate pre-launch gates.

5. Corrections

If you identify a reproducible error or an outdated source, send the affected calculator, inputs and supporting reference through the contact page. Corrections should update both the result logic and the explanation/source record when necessary.