Tonnage in shipping is confusing because the word means different things in different contexts. A "ton" in shipping can refer to weight, volume, or vessel capacity — and the specific type of tonnage determines how freight is measured, how ports assess fees, and how vessel capacity is calculated.
Here's a clear breakdown of every type of tonnage you'll encounter in logistics.
Weight-based tonnage
Metric ton
1,000 kilograms (2,204.6 lbs). The standard unit of weight measurement in international shipping. When someone says "ton" in an international freight context, they usually mean metric ton.
Short ton
2,000 lbs (907.2 kg). The standard ton in the United States. Used primarily in domestic US freight.
Long ton
2,240 lbs (1,016 kg). The traditional British ton. Still used in some maritime contexts but increasingly replaced by the metric ton.
Volume-based tonnage
Measurement ton (freight ton)
One cubic meter of cargo space (approximately 35.3 cubic feet). Used in ocean freight pricing when cargo is light relative to its volume — the carrier charges based on how much space the cargo occupies rather than how much it weighs.
Revenue ton
The greater of the weight ton or the measurement ton for a specific shipment. This is how ocean carriers and LTL carriers determine which measurement to use for pricing — they charge based on whichever yields the higher revenue. If your cargo is heavy and dense, you pay by weight. If it's light and bulky, you pay by volume.
Vessel capacity tonnage
Gross tonnage (GT)
A measure of the total internal volume of a vessel — not weight. One gross ton equals 100 cubic feet of enclosed space. Gross tonnage is used for port fees, canal tolls, manning regulations, and safety requirements. A large container vessel might have a gross tonnage of 150,000+.
Net tonnage (NT)
The volume of the vessel's cargo-carrying spaces only — excluding crew quarters, engine rooms, and other non-cargo areas. Net tonnage is used for port charges and canal dues in some jurisdictions.
Deadweight tonnage (DWT)
The total weight a vessel can carry — including cargo, fuel, water, stores, crew, and passengers. DWT is the most relevant capacity measure for freight shippers because it indicates how much cargo the vessel can actually transport. A large bulk carrier might have a DWT of 200,000+ metric tons.
Displacement tonnage
The actual weight of the vessel itself — measured by the weight of water it displaces. Used primarily for naval vessels and in vessel design, not in commercial freight.
TEU — container tonnage
TEU (Twenty-foot Equivalent Unit) is the standard measure of container vessel capacity. One TEU equals one standard 20-foot container. A 40-foot container equals 2 TEU. Modern ultra-large container vessels carry 20,000+ TEU.
How Total Connection uses tonnage in your quotes
We quote ocean freight based on the revenue ton — the greater of weight or volume — to give you accurate pricing based on how carriers actually charge. Our team converts between tonnage types so your quotes are clear and comparable. Call 732-817-0401 or request a quote.
