The method behind the calculation
Assumptions and limits
Inputs are first converted to cm and kg. Per-package billing rounds each physical box before summing. Shipment billing rounds the greater of total actual and total dimensional weight. The two methods can differ. Surcharges, dimension rounding and minimum freight charges are excluded.
Follow the example calculation.
100 boxes at 60 × 40 × 40 cm / 12 kg, plus 20 boxes at 30 × 30 × 30 cm / 15 kg, total 10.14 m³ and 1,500 kg. With divisor 5,000 and no rounding, total dimensional weight is 2,028 kg, while per-package chargeable weight is 2,220 kg.
Frequently asked questions
Why can shipment and per-package billing differ?
Per-package billing takes the greater of actual and dimensional weight for each box. Shipment billing sums each weight type first, then takes the greater total. Mixing dense and lightweight boxes can produce different charges.
When does rounding happen?
Per-package mode rounds each physical box. Shipment mode rounds the total chargeable weight once. Select the increment and basis used by your carrier.
Can I enter inches and pounds?
Yes. Choose inches and pounds. Numbers are interpreted in the selected unit; changing the unit does not convert the numbers already entered. Results are shown in cm, m³ and kg.
Related sources
Inputs are processed on this device. Example figures are not quotes or live market prices.