Bulk carriers are segregated into six major size categories: small, handysize, handymax, panamax, capesize, and very large. Very large bulk and ore carriers fall into the capesize category but are often considered separately.

Categories as per regions

Categories occur in regional trade, such as Kamsarmax, Seawaymax, Setouchmax, Dunkirkmax, and Newcastlemax also appear in regional trade.

"Kamsarmax" : Maximum length overall 229 meters refers to a new type of ships, larger than panamax, that are suitable for berthing at the Port of Kamsar (Republic of Guinea), where the major loading terminal of bauxite is restricted to vessels not more than 229 meters.

"Newcastlemax" : Maximum beam 50 meters, and maximum length overall of 300 meters Refers to the largest vessel able to enter the port of Newcastle, Australia at about 185,000 DWT

"Setouchmax" : About 203,000 DWT, being the largest vessels able to navigate the Setouchi Sea, Japan

"Seawaymax" : LOA 226 m max / 7.92 m draft. Refers to the largest vessel that can pass through the canal locks of the St. Lawrence Seaway (Great Lakes, Canada)

"Malaccamax" : LOA 330 m / 20 m draft / 300,000 DWT, Refers to the largest vessel that can pass through the Straits of Malacca.

"Dunkirkmax" : Maximum allowable beam = 45 m / LOA 289 m. max (175,000 DWT approx) for the eastern harbour lock in the Port of Dunkirk (France)

Mini-bulk carriers are prevalent in the category of small vessels with a capacity of under 10,000 DWT. Mini-bulk carriers carry from 500 to 2,500 tons, have a single hold, and are designed for river transport. They are often built to be able to pass under bridges and have small crews of three to eight people.

Handysize and Handymax ships are general purpose in nature. These two segments represent 71% of all bulk carriers over 10,000 DWT and also have the highest rate of growth. This is partly due to new regulations coming into effect which put greater constraints on the building of larger vessels.[28] Handymax ships are typically 150–200 m in length and 52,000 – 58,000 DWT with five cargo holds and four cranes. These ships are also general purpose in nature.

The size of a Panamax vessel is limited by the Panama canal's lock chambers, which can accommodate ships with a beam of up to 32.31 m, a length overall of up to 294.13 m, and a draft of up to 12.04 m.

Capesize ships are too large to traverse the Panama canal and must round Cape Horn to travel between the Pacific and Atlantic oceans. Earlier, capesize ships could not traverse the Suez and needed to go around the Cape of Good Hope. Recent deepening of the Suez canal to 66 ft (20 m) permits most capesize ships to pass through it.

Capesize bulk carriers are specialized: 93% of their cargo is iron ore and coal. Some ships on the Great Lakes Waterway exceed Panamax dimensions but they are limited to use on the Great Lakes as they cannot pass through the smaller St. Lawrence Seaway to the ocean. Very large ore carriers and very large bulk carriers are a subset of the capesize category reserved for vessels over 200,000 DWT. Carriers of this size are almost always designed to carry iron ore.

In October 2022, Mitsui O.S.K. Lines (MOL)'s bulk carrier Shofu Maru arrived in Newcastle on its maiden voyage, becoming the first bulk carrier to be partially powered by hard sail wind power propulsion technology. A five percent fuel savings was anticipated.