Each mode of transport, land,sea, airplane, or rail, partial loads (containers, trucks or wagons) use a different system for calculating the freight cost per unit, the base on which the shipping cost is calculated.
W/M rate: the rate usually applies to the weight W calculated in metric tons (1,000 kg) or to the volume M (measurement), calculated in cubic metres (CBM), whichever is greater, in favour of the shipping company.
W rate: in some cases it is calculated only on weight W.
ML rate: a rate per linear metre is sometimes applied when transporting vehicles on RORO ships.
This rates is calculated on the weight (kg), with a maximum weight/measurement ratio of 1,000 kg: 6 CBM; if the volume of the goods exceeds this ratio (1:6) the freight cost for the unit is obtained by dividing the volume by 6.
This rates is calculated in 100s of kg, with a maximum weight/measurement ratio of 1000 kg: 3 CBM; if the volume of the goods exceeds this ratio (1:3) the freight cost for the unit is obtained by dividing the volume by 3.
This rate is calculated on weight, but it varies depending on the characteristics of the goods.