Calculation Methodology

Formula-first development

Each tool starts with a written formula and unit model. Pure calculation functions are regression-tested separately from the browser interface.

Source hierarchy

Carrier service guides, USPS Postal Explorer, NMFTA, IATA and carrier equipment specifications are preferred over secondary summaries.

Review dates

A review date means the underlying formula or source record was checked; it does not imply every carrier contract uses the same rule.

Limitations are part of the result

Tools state when they are geometry estimates, density estimates or planning conventions rather than certified load plans or binding classifications.