Container Types (20GP, 40GP, 40HQ)
The three standard dry shipping containers used for sea freight, with approximate internal volumes and how to choose between them.
TL;DR: The most common dry containers are the 20GP, 40GP and 40HQ. Choose based on both the volume and the weight of your cargo, not volume alone.
A 20GP (20-foot general purpose) container has about 33 CBM of internal volume. A 40GP has about 67 CBM, and a 40HQ (40-foot high cube) is about 30 cm taller, with roughly 76 CBM. Practical loadable volume is lower, often by 10 to 15 percent, because cartons and pallets never fill every corner.
Weight limits are just as important. Maximum payload varies by carrier and container, and road rules at the destination may set a lower practical limit. A 40-foot container usually allows only a little more weight than a 20-foot one, even though it has twice the space.
This matters for dense cargo. Glass mosaic sheets in cartons on wooden crates or pallets can reach the weight limit well before the container looks full. In that case, two 20GP containers may carry more total weight than one 40GP. Light, bulky goods, on the other hand, make best use of a 40HQ.
Other types exist, such as open top, flat rack and refrigerated containers, but tile and similar goods normally ship in standard dry boxes. Ask your supplier for the gross weight and CBM of the order, then let your forwarder suggest the right mix.
See also FCL, TEU and CBM.