How is cross-border shipping cost calculated?
Freight = chargeable weight × unit rate + surcharges. Chargeable weight is the greater of actual weight and volumetric weight, so bulky lightweight goods are billed on volume and small heavy goods on actual weight.
For a specific line, the rate also depends on the destination zone (rates can differ within one country), weight tiers (under 2kg, 2-10kg, 10-21kg, over 21kg — declining rates) and goods category (general, battery and sensitive goods carry different uplifts). The on-site rate calculator applies these rules automatically from weight and dimensions.