Calculation methodology

Geometry and units

Material and volume tools convert all measurements to a common internal metric basis before calculating. Results are then converted for display using standard geometric conversion factors.

Dimensions entered in different unit systems are converted when the unit selector changes so that the physical size remains the same.

Construction estimates

Gravel weight equals order volume multiplied by user-supplied bulk density. Concrete bag quantity uses the finished yield printed by the manufacturer rather than an assumed concrete density.

Waste is applied after base geometric volume. Costs use the price entered by the user and do not include unlisted delivery or service charges.

Freight calculations

CBM is calculated from external packed dimensions. Dimensional weight compares actual and volumetric weight package by package. The container planner uses a three-dimensional placement heuristic with permitted orientations and payload checks.

Rounding and validation

Displayed values are rounded for readability, while calculations retain greater precision. Whole physical items such as bags and truckloads are rounded up. Zero or impossible dimensions are rejected or reported as unpacked.

Sources and quality checks

Unit definitions and conversion factors are checked against BIPM or NIST references. Freight definitions and reference dimensions are checked against carrier and industry documentation. Material density, finished yield and price remain user inputs because they vary by product and market.

Quality checks include known worked examples, metric-to-imperial invariance, invalid-input handling, whole-item rounding and comparison of displayed totals with intermediate values. The current methodology review was completed in August 2026.