Guides

Worked examples for billable weight, each checked against the calculator’s own engine.

• How to calculate dimensional weight for multiple boxes

  Work out billable weight carton by carton, then multiply and add. A worked three-carton example, why comparing shipment totals undercharges, and unit conversion.

• Dimensional weight vs actual weight: which one is billed?

  The carrier bills the higher of scale weight and dimensional weight, rounded up. Three worked cartons, including one where a smaller box would not lower the bill.

• USPS dimensional weight calculator

  From 12 July 2026 USPS uses 139 for parcels over 1,728 in³, with each side rounded up to a whole inch. Check a carton, step by step, in inches or centimetres.

• UPS dimensional weight calculator

  UPS bills the greater of actual and dimensional weight: 139 for Daily Rates, 166 for Retail, each side rounded up to a whole inch. Check a carton step by step.

• FedEx dimensional weight calculator

  FedEx divides by 139 and, since 18 August 2025, rounds every fraction of an inch up. Check a package step by step, with the 40 lb and 90 lb minimums flagged.

• DHL Express volumetric weight calculator

  DHL Express divides each piece by 5000 and rounds up to 0.5 kg; a shipment over 30 kg is rounded up to a whole kg. Check a parcel step by step in cm or inches.

• 5000 vs 6000: how the divisor changes the bill

  A 5000 divisor makes the same carton heavier than 6000. What each one means, which services publish them, and the same shipment worked both ways.

• Amazon FBA dimensional weight: units and inbound cartons

  Amazon divides unit volume by 139, assumes 2 inches for bulky items, and caps inbound boxes at 36 × 25 × 25 in and 50 lb. Worked examples for units and cartons.

Last updated: 28 October 2026. Billable weight only: surcharges, minimum charges and your negotiated rates are not included.