Stowage Factor (SF) is the density of the cargo in the ship’s hold. In the shipping business, Stowage Factor (SF) is a very important piece of information. 

Due to the ship’s cubic capacity, a ship has only a limited volume (space) in her holds. In some cases:

• Light Cargo: the ship’s holds are full before all the ship’s deadweight cargo capacity is utilized 
• Heavy Cargo: full deadweight capacity can be reached with space still available in holds, but that space is unusable

In the shipping business, some historic measurement systems are still in use, for example, variations of the old English system (imperial system) of weights and measures are still frequently used for Stowage Factor (SF) – cubic feet to one ton (ft3/ton). 

Stowage Factor of general cargoes

   Stowage factor (SF) indicates how many cubic metres (or cubic feet) of space one metric tonne of a particular type of cargo occupies in a hold of a cargo ship. It is calculated as the ratio of the stowage space required under normal conditions, including the stowage losses caused by the means of transportation and packaging, to the weight of the cargo. (Wikipedia)

Stowage Factor of bulk cargoes

  Stowage factor (SF) indicates how many cubic metres (or cubic feet) of space one metric tonne of a particular type of cargo occupies in a hold of a cargo ship. It is calculated as the ratio of the stowage space required under normal conditions, including the stowage losses caused by the means of transportation and packaging, to the weight of the cargo. (Wikipedia)