Each product has a specific volume, and every inventory or cargo space has a limit on the volume it can accommodate.
Inventory capacity is constrained by both mass and volume. Some products, raw materials, and refined materials have a high mass but low volume, while others are the opposite. These factors should be carefully considered during production. Warehouses are designed to store significantly more mass than volume, whereas Fluid Storage Terminals can accommodate more volume but are heavily restricted in terms of mass. In addition each ship cargo will accomdate varying mass and volume.
You can view all products mass and volume here: products