Net weight is the goods alone. Gross weight is the goods plus their packaging. Tare weight is the empty container. Volumetric or dimensional weight is not a weight at all — it is a volume converted into a notional weight by a fixed divisor, so that a carrier can charge for the space a light, bulky consignment occupies. On a construction or FF&E project these four numbers decide how much you pay, whether the container is legal to load, and whether it is legal to move on the road at the far end. They regularly disagree with each other, and the one that disagrees loudest is usually the one nobody checked.
What do the weights on your shipping documents actually mean?
- Net weight (NW). The product itself with no packaging. This is the figure customs authorities most often want on the commercial invoice, and in many tariff lines the duty is assessed against it.
- Gross weight (GW). Net weight plus cartons, pallets, corner protectors, strapping and any timber. On furniture and lighting the difference between net and gross is far larger than buyers expect — heavy protective packing is the reason the goods survive the journey.
- Tare weight. The empty container. It is stencilled on the container door and typically runs around 2.2 tonnes for a 20ft general purpose box and around 3.7 to 3.9 tonnes for a 40ft, varying by build.
- Verified Gross Mass (VGM). Tare plus everything inside. This is a regulated declaration, not an estimate — see below.
- Volumetric or dimensional weight. Volume converted to a notional weight using a divisor set by the carrier or the mode. It exists because carriers sell space as well as capacity.
- Chargeable weight. Whichever of actual weight and volumetric weight is greater. This is the number the freight invoice is calculated on.
How is chargeable weight calculated?
Air freight. The standard IATA volumetric divisor is 6,000 cm³ per kilogram, which is the same as saying one cubic metre is treated as 167 kg. Express integrators commonly use a stricter divisor of 5,000 cm³ per kilogram, or 200 kg per cubic metre. A pallet of light fixtures at 40 kg actual and 1.2 m³ volume is charged as roughly 200 kg at the IATA divisor — five times the scale weight.
Less-than-container-load sea freight. LCL is quoted on a weight-or-measure basis: one cubic metre is set equal to one tonne, and you are charged on whichever is greater, expressed as a revenue ton. This is why an LCL quotation that looks cheap per cubic metre can settle expensively on a dense product like tile or stone.
Full container load. There is no volumetric calculation at all. You buy the box. The economics flip completely: the objective is no longer to minimise chargeable weight but to fill the container as completely as both the cubic space and the payload limit allow. FBM Sourcing ships project orders as full container loads consolidated for one client; we do not handle loose freight. Understanding the LCL basis still matters, because buyers meet it in quotations from other parties and in the early stages of a project when quantities are not yet fixed.
Why a furniture container runs out of space and a tile container runs out of weight
Every container has two limits, and a project package almost never hits both at once.
| Container | Approximate internal volume | Typical maximum payload | Which limit usually bites |
|---|---|---|---|
| 20ft general purpose | ~33 m³ | ~28 tonnes | Weight, on dense cargo |
| 40ft general purpose | ~67 m³ | ~26–27 tonnes | Volume, on most FF&E |
| 40ft high cube | ~76 m³ | ~26–27 tonnes | Volume, almost always |
Confirm the exact payload with the carrier: the maximum gross mass permitted varies by container build, by trade lane and by the equipment actually allocated.
The practical consequences follow directly. A 40ft high cube of hotel casegoods, upholstery and lighting will cube out at perhaps 8 to 12 tonnes — well under half the permitted payload — because packed furniture is mostly air. A 20ft of porcelain tile or stone slabs will hit the weight limit with the container visibly part empty. The correct response is not to force one product into one box but to plan the consolidation across the package, pairing dense categories with bulky ones so that both limits are approached together. That is a package-level decision, and it is one of the reasons the categories on a project are better bought together than separately, as set out in what a whole-hotel FF&E and building materials package covers.
A realistic loading efficiency is 85 to 90 per cent of nominal internal volume. Packaging is rectangular, product is not, and the last metre of a container is always the most expensive to fill.
Sourcing this for a commercial project?
FBM Sourcing works with project owners, developers, main contractors and FF&E contractors on hotel, apartment, school, office and other commercial building projects. Send us your BOQ, drawings or product list — our team will review it and get back to you.
What is VGM and who is responsible for it?
Under SOLAS Chapter VI, the shipper named on the bill of lading must declare a Verified Gross Mass for every packed container before it may be loaded aboard a vessel. There are two permitted methods: weighing the packed container on calibrated equipment, or adding the certified weights of all cargo, dunnage and packaging to the container tare. The declaration must be signed by a named person on behalf of the shipper.
No VGM means no loading. This is not a documentary formality that can be corrected later — a container without a declared VGM is left on the terminal, and the resulting storage and re-booking costs land on the cargo. For a project buyer the point is simply to know who is making the declaration on your behalf and on what basis, because an estimate presented as a verified figure is a real liability.
The limit most project buyers discover too late: the road at the destination
A container can be perfectly legal at sea and illegal on the road. In the United States, the federal gross vehicle weight limit on the Interstate system is 80,000 lb (about 36.3 tonnes) for the tractor, chassis and container combined, subject to the bridge formula and axle limits. Once the tractor and chassis are deducted, the cargo that can legally move on a standard road move is commonly in the region of 19 to 20 tonnes — substantially less than the container itself is permitted to carry at sea. Comparable limits apply in the EU, Australia and elsewhere, with their own permit regimes.
The practical rule for dense products is therefore to plan the load against the destination road limit, not against the container payload. Overweight permits and specialised chassis exist, but they cost money and time and they need arranging before the box is loaded in China, not after it lands. How the box then reaches site is covered in how door-to-site delivery works for construction project orders.
What the packing list must show
A packing list that only totals the shipment is not usable on a construction site. For a project order it should show, per carton or per crate:
- Carton or crate number, and the mark it carries on the outside
- The schedule or BOQ reference for what is inside — the room number, the door mark, the fixture type code
- Quantity, net weight, gross weight, and dimensions with the resulting volume
- Which container it is loaded in, where a shipment spans more than one
Totals must reconcile: the sum of carton gross weights plus dunnage plus tare must equal the declared VGM, and the sum of carton volumes must be consistent with the container used. Where those numbers do not reconcile, something has been estimated, and estimated packing lists are the origin of most short-shipment disputes. What the corresponding loading record should contain is set out in what a container loading report should show for a commercial project.
The same figures feed the customs entry, alongside the tariff classification — see what HS codes apply to furniture and building materials imports — and they roll up into the landed cost calculation described in how to calculate landed cost for a China project order.
Three mistakes that cost real money
- Quoting freight against net weight. Net weight excludes the packaging, and on furniture the packaging can add 20 to 30 per cent. A budget built on net weight is short before the first container ships.
- Comparing an air quotation and a sea quotation on the same tonnage. They are different quantities. Air is charged on chargeable weight with a volumetric divisor; FCL sea is charged per box. The comparison only becomes meaningful once both are converted to cost per unit delivered, which is the framing used in air freight vs sea freight on a project order.
- Planning the load without the destination road limit. The most expensive version of this is a dense container that has to be de-stuffed and re-loaded at the port because it cannot legally be trucked to site.
About FBM Sourcing
FBM Sourcing manages the entire China procurement package for overseas construction projects. Sourcing since 2014, we have shipped 1,000+ containers to project sites in 20+ countries, working with project owners, developers, main contractors and FF&E contractors on hotels, apartment buildings, schools, offices and other commercial buildings. All quotations, invoices and shipping documents are issued by FBM Sourcing — you deal with us, and we carry the responsibility. For suppliers you nominate, we charge a 5% commission; for products we source for you, we quote a direct price.
If you want the weight, volume and consolidation plan checked before a container is booked, send us the packing list or the product schedule at https://fbmsourcing.com/china-building-materials-ffe-procurement/.
Sourcing this for a commercial project?
FBM Sourcing works with project owners, developers, main contractors and FF&E contractors on hotel, apartment, school, office and other commercial building projects. Send us your BOQ, drawings or product list — our team will review it and get back to you.
Frequently asked questions
What is the difference between gross weight and net weight?
Net weight is the goods alone with no packaging. Gross weight is the goods plus all packaging — cartons, pallets, timber, strapping and protection. On packed furniture and lighting the gross weight can exceed the net weight by 20 to 30 per cent, so freight and handling budgets built on net weight are understated.
How is volumetric weight calculated for air freight?
The standard IATA volumetric divisor is 6,000 cubic centimetres per kilogram, equivalent to treating one cubic metre as 167 kg. Express integrators commonly apply a stricter divisor of 5,000 cubic centimetres per kilogram, or 200 kg per cubic metre. You are charged on the greater of actual and volumetric weight, known as the chargeable weight.
Does volumetric weight apply to a full container load?
No. On FCL you buy the container itself, so there is no volumetric calculation. The two limits that matter are the internal cubic capacity and the maximum payload, and the objective is to approach both together by consolidating dense and bulky categories in the same box.
What is VGM and who declares it?
Verified Gross Mass is the total weight of a packed container including its tare, required under SOLAS Chapter VI before a container may be loaded aboard a vessel. The shipper named on the bill of lading declares it, either by weighing the packed container or by summing certified cargo, packaging and dunnage weights with the tare. Without a VGM declaration the container is not loaded.
Why can a legally loaded container be illegal on the road?
Road authorities limit the weight of the whole vehicle combination, not just the box. In the United States the federal Interstate limit is 80,000 lb gross for tractor, chassis and container together, which after deducting the equipment commonly leaves roughly 19 to 20 tonnes of cargo — less than the container is permitted to carry at sea. Dense loads should therefore be planned against the destination road limit.
