It involve cargo volume and weight as well as transport rates.
Fcl container volume.
Fcl freight is considered to be the most optimized container shipping method.
So the cost per freight is higher in the case of lcl booking although in terms of the total cost it is the more economical option.
Fcl container costs are mostly made up of lump sums per container in contrast to lcl container costs which are made up of weight and volume of the cargo.
Fcl is intended to designate a container loaded to its allowable maximum weight or volume but fcl in practice on ocean freight does not always mean a full payload or capacity many companies will prefer to keep a mostly full container as a single container load to simplify logistics and increase security compared to sharing a container with.
Unlike fcl which usually has a flat rate per container lcl is charged based on the volume set in cubic meters.
The general rule of thumb is to go with lcl when shipping low volume shipments between 2 and 13m 3 and fcl for higher volume shipments 13m 3 and above even though you may not completely fill the container.
Full container loading is that goods need about 20 feet or even 40 feet of space when the importer or exporter has enough goods to fill the full container.
Lcl shipping is a cost effective solution for smaller shipments as you only need to pay for the volume space used.
In terms of total costs booking an fcl container will be more expensive given the sheer volume.
However if the dimension wise cost is considered the fcl booking is generally cheaper.