Calculation Methodology and Sources
DimWeightPro performs transparent package-volume arithmetic. It does not query carrier rating APIs, guarantee a shipping quote, or replace a current carrier agreement.
How calculations work
The calculator multiplies length, width, and height, divides by the selected DIM factor, and compares the result with actual weight. Estimated carrier cost is the calculated billable weight multiplied by the rate entered by the user and package quantity.
Displayed results are estimates. Carrier-specific rounding, minimum billable weights, surcharges, size thresholds, parcel shape, service eligibility, destination, and contract terms are not fully modeled.
How carrier information is maintained
Carrier claims on the guide pages are checked against publicly available carrier documentation. We prefer first-party pages, rate guides, and postal manuals. Pages link to the source used so readers can inspect the current rule.
Limits and review policy
Published rules can change, and negotiated agreements may override general guidance. Users should confirm final billing rules directly with their carrier before purchasing a label or making packaging decisions. If a claim cannot be verified from an official source, it is omitted or marked for review rather than guessed.
Last reviewed: September 23, 2026
Frequently asked questions
Does DimWeightPro provide carrier quotes?
No. It estimates costs from user-entered rates and does not replace a carrier quote or invoice.
Where do carrier factors come from?
Guide pages use linked official carrier documentation and state the service context available in that source.
How often can carrier rules change?
Carriers can update rate guides and service rules at any time, while customer contracts may contain separate terms.