Tonnage

Tanker sizes

Published 20 August 2026 · updated 17 October 2026

Tankers are grouped into deadweight bands (deadweight is the weight a ship can carry), just like dry cargo ships. But for tankers the band tells a broker less. A 110,000 tonne tanker may be an Aframax carrying fuel oil or an LR2 carrying jet fuel. A cargo that suits one will not be allowed on the other. The bands give you the words, but the trade and the tanks decide the fixture.

The bands

These are the usual names and the deadweight ranges the trade usually gives them. Every boundary here is a convention, not a standard. Different reports differ by several thousand tonnes on most of them.

Class	Deadweight	What it carries
Handy / Coastal	under about 25,000 mt	Short sea products, fuel delivery to other ships, edible oils. Small cargoes into ports with limited draught (water depth), which is usually the whole reason this size is chosen.
MR	about 25,000 to 55,000 mt	Medium Range. The standard clean product tanker: gasoline, gasoil, jet fuel and naphtha, in coated tanks.
LR1	about 55,000 to 80,000 mt	Long Range 1. The same hull size as a dry Panamax, coated, carrying products on longer routes.
LR2	about 80,000 to 120,000 mt	Long Range 2. A coated Aframax, carrying clean products and naphtha over long distances.
Aframax	about 80,000 to 120,000 mt	Crude and dirty products in uncoated tanks. The same tonnage as an LR2, but a different ship commercially.
Suezmax	about 120,000 to 200,000 mt	Crude. Sized so it can pass through the Suez Canal fully loaded.
VLCC	about 200,000 to 320,000 mt	Very Large Crude Carrier. Long distance crude between deepwater terminals and offshore moorings.
ULCC	above about 320,000 mt	Ultra Large Crude Carrier. Rare. Its draught decides where it can go. Often that means it cannot come alongside a berth at all.

The two crude classes in the middle are compared in detail, with cargo sizes and routes, in Aframax vs Suezmax.

Named for a canal, a strait or a rate sheet

Three of those names describe a ship and the others describe something else. Knowing which is which stops a broker treating them as one single scale.

Suezmax comes from the canal. The limit is the allowed loaded draught and beam (width), not a tonnage. The canal authority has deepened the channel more than once, so the limit keeps changing. A ship called Suezmax when it was built cannot automatically pass through under today's rules at today's draught.
Panamax, in tanker work, refers to the locks of the Panama Canal. It is a beam and a length, not a deadweight. Since the larger locks opened in 2016, the word describes a ship smaller than the canal it is named after.
Malaccamax comes from the Strait of Malacca, and again the limit is draught. This is why a loaded VLCC sometimes takes a longer route.
Aframax is not a place at all. It comes from the Average Freight Rate Assessment scale, an old system for pricing tanker voyages. That system grouped ships into size brackets for pricing. The bracket lasted longer than the rate system and became a ship class.

MR, LR1 and LR2 come from the same business language as Aframax. They are rate-sheet brackets that became fixed names. VLCC and ULCC are the only names that simply say how big the ship is.

Clean and dirty is the real dividing line

Dirty means crude oil, fuel oil, residuals and bitumen. Clean means refined products: gasoline, gasoil, jet fuel, naphtha, and also vegetable oils and the easier chemicals. The difference is not about cleanliness in the everyday sense. It is about what the last cargo leaves in the tank, and whether the next charterer will accept it.

The physical difference is the tank surface. A crude carrier has bare steel tanks, at most coated against rust. A product tanker's cargo tanks are lined, usually with epoxy or zinc silicate. That lining is what makes the ship acceptable for clean cargo. Different linings suit different cargoes. Zinc silicate handles methanol and solvents but not acids, while epoxy takes most clean petroleum products and vegetable oils. The strongest chemicals need stainless steel tanks and a specially built parcel tanker.

So the coating is what allows the ship to carry clean cargo, and it can be damaged. If a coated MR carries a dirty cargo, it must be cleaned before charterers of clean cargo will accept it again. That costs real money: cleaning time, dirty wash water (slops) to get rid of, and days out of the market. Some coatings do not survive the cargo or the cleaning at all. This is exactly why charterers ask for the last three cargoes. The answer, not the class name, tells them what the tanks have been through.

Segregation, and how many grades it can carry at once

Another question separates two tankers of the same size: how many separate cargoes (parcels) can it keep apart? That depends on the number of cargo tanks, and more importantly on whether the tanks have their own pumps and pipelines. A ship with a dozen tanks served by three pump rooms can carry three grades fully apart, not twelve. Charterers state their segregation needs in the enquiry. A ship that cannot meet them is rejected, whatever its deadweight.

Chemical and parcel tankers have one more classification: IMO Type 1, 2 or 3 under the IBC Code. It describes how well the ship keeps its cargo contained if the ship is damaged. Type 1 is for the most dangerous cargoes and needs the most protective tank layout. It is a standard for containing cargo, not a size, and people reading tanker records for the first time often confuse the two.

The hazard labels in AIS data are not size classes

In records taken from AIS (the ship tracking signal), the vessel type comes from a numbered table that the ship broadcasts. That table splits cargo ships and tankers by the cargo hazard they declare. So the type text arrives as labels like Hazard A (Major), Hazard B and Hazard D (Recognisable). These look like grades and are often mistaken for a size or quality ranking, but they are neither: they describe what the ship says it is carrying.

2,427

Ships in the register whose type is Cargo Hazard A (Major), with a mean deadweight of 71,323. That is a hazard declaration in the same column as Tanker and Cargo, covering ships of every size. If you filter on type, it acts like a class, but it is not one.

This causes a practical problem. A broker filters for type equals Tanker and gets a result that looks complete. But the result leaves out, with no warning, every ship that broadcasts a type with a hazard label instead. Those groups contain real chemical and product tankers. The fix is to treat the hazard labels as a second filter, used together with the type, not in place of it.

Why a deadweight filter mis-sorts tankers

The register holds 15,458 tankers. Of those, 13,540 have a deadweight, and a band search can never return the rest. This is the same gap that hides the 26,304 ships across the whole register that have an IMO number but no recorded deadweight.

57,332

The mean deadweight of every tanker in the register. It falls right in the LR1 band, yet it describes almost no real fixture. Tanker sizes are not spread evenly around the average. They group at MR and again at the crude sizes.

Search 80,000 to 120,000 tonnes and the results show crude Aframaxes and clean LR2s in one list. These ships share a hull size but no cargoes. Search 45,000 and an MR product tanker appears next to a stainless steel chemical tanker whose daily rate is set in a different market. Put a coastal tanker in the Handy band, and nothing in that name says whether it is coated. In every case the tonnage was right and the ship was wrong.

Deadweight answers one question: can the ship carry the cargo? Coating, segregation and the last three cargoes answer another: will anyone let it load the cargo? A tonnage list sorted only on the first will always show ships that cannot take the cargo and hide ships that can. The broker who checks the second question is the one who fixes the deal.

References

INTERTANKO (International Association of Independent Tanker Owners), About INTERTANKO. intertanko.com
Suez Canal Authority, Rules of Navigation. suezcanal.gov.eg
IMO, International Convention for the Prevention of Pollution from Ships (MARPOL), 1973, as modified by the 1978 Protocol. imo.org
IMO, Carriage of chemicals by ship, on the International Bulk Chemical Code (IBC Code). imo.org
ITU, Recommendation ITU-R M.1371: Technical characteristics for a VHF automatic identification system using time division multiple access in the maritime mobile service. itu.int

Aframax vs SuezmaxTwo crude tanker classes, one named after a rate scale and one after a canal. Cargo sizes, routes, and where the published ranges disagree. Dry bulk vessel sizesHandysize to Capesize: where the deadweight bands sit, why their edges are trade habits, and how many ships fall in each. Reading a ship's particularsWhat each figure on a vessel description limits, why GRT measures volume, and why draught rules a ship out long before deadweight does. Position list vs AIS vs port line-upThree things people often mix up in chartering: where a ship is, when it is free next, and what the port authority expects at the berth. Ship types and what they carryThe physical state of the cargo decides the type of ship, and a register’s type field hides most of the differences a broker needs.

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