Dimensional-weight rounding: worked parcel examples

Separate measurement rounding from weight rounding

A carrier may first round each outside dimension, then calculate dimensional weight, then round the resulting chargeable weight to a billing increment. Those are separate operations. A calculator that rounds only the final displayed number may not reproduce the invoice.

For example, dimensions of 19.6 × 15.6 × 11.6 inches may become 20 × 16 × 12 inches under a whole-inch measurement rule. At a 139 divisor, the rounded-dimension cube produces 27.63 lb before chargeable-weight rounding.

Compare per-parcel and shipment rounding

If the applicable rule rounds 27.63 lb up to 28 lb per parcel, ten identical parcels produce a 280 lb dimensional basis. Multiplying the unrounded result first produces 276.3 lb, which is not the same billing model.

Actual weight must go through the same contract check. If each parcel weighs 29 lb, actual weight controls; if each weighs 24 lb, dimensional weight controls in this example.

• Do not round intermediate cube without a stated rule.
• Do not combine unlike parcel types.
• Keep quantity outside the per-parcel comparison unless instructed otherwise.

Turn discrepancies into a repeatable check

When the carrier invoice differs, compare measured dimensions, manifest dimensions, factor, actual weight, and rounding sequence one at a time. Save one confirmed example for each carrier service so future packaging changes can be tested against a known method.