Chargeable weight: why a light pallet can cost like a heavy one

Chargeable weight is the greater of what a consignment weighs and what its volume is deemed to weigh, because a vehicle runs out of space long before it runs out of lifting capacity. Air freight divides length by width by height in centimetres by 6,000 — about 167 kg per cubic metre — while express networks commonly use 5,000 and road freight charges by space taken instead. This sets out the arithmetic, a worked example and how to reduce the figure.

What is chargeable weight?

Chargeable weight is the figure a freight quote is actually built on, and it is the greater of two numbers: what the consignment weighs, and what the space it occupies is deemed to weigh. Whichever is higher is the one you pay against.

The logic is capacity rather than greed. An aircraft or a trailer runs out of volume long before it runs out of lifting capacity, so a carrier that priced only by the kilogram would give away its deck space on anything bulky and light. The volumetric figure is how space gets converted into a billable unit.

This is why a pallet of cushions and a pallet of bolts can be quoted at similar money despite weighing nothing like the same. One is paying for mass and the other for room, and the quote does not usually say which.

How is volumetric weight calculated?

Length by width by height in centimetres, divided by a number the carrier publishes. For air freight the industry standard divisor is 6,000.

Volumetric weight in kg = (length cm × width cm × height cm) ÷ 6,000

That divisor encodes a density. A cubic metre is 1,000,000 cubic centimetres, so dividing by 6,000 gives 166.67 kg — which is why air freight is often described as charging about 167 kg per cubic metre. Anything less dense than that pays for its volume rather than its mass.

Why do different carriers give different answers?

Because the divisor is a commercial convention, not a rule. There is no regulator setting it, so each network publishes its own, and a smaller divisor produces a bigger volumetric weight for exactly the same box.

The practical consequence is that comparing two quotes means comparing two divisors as well as two rates. A carrier with a keener rate and a 5,000 divisor can be dearer than one with a higher rate and 6,000, and nothing on the quote makes that obvious unless you ask.

What does that look like on a real consignment?

Take one pallet measuring 120 by 80 by 100 centimetres — a standard Euro pallet with a metre of height on it — carrying 60 kg of goods.

The consignment weighs 60 kg and is charged as at least 160. That is not an error and it is not negotiable — it is the pallet claiming a metre of height it has not filled with mass. Reduce the height to 60 centimetres and the volumetric weight drops to 96 kg, below which the actual weight starts to matter again.

Which weight do you pay on?

The higher one, always, and per consignment rather than per item. The comparison is made after the goods are packed and measured as they will travel, which is the detail that catches people who calculate it from the product dimensions.

Two things get added to the box before the measurement happens. Packaging is part of the dimensions, and so is the pallet: a 15-centimetre pallet base under a 100-centimetre stack makes the shipment 115 centimetres tall for charging purposes. Our pallet sizes and vehicle capacity article covers the standard footprints.

Rounding is also conventional. Carriers commonly round up to the next half or whole kilogram and measure to the next whole centimetre, so a figure that lands just over a threshold goes up rather than to the nearest.

Does road freight work the same way?

No, and this is where the air-freight formula stops helping. Road freight is usually priced by the space the consignment occupies on the vehicle rather than by a divisor — pallet spaces on a pallet network, or loading metres on a trailer.

A loading metre is one metre of trailer length across its full width, so a trailer is sold as a number of them. A consignment that is half a metre long but cannot be stacked or loaded alongside anything still consumes the metre, which is the road equivalent of the volumetric problem: the charge follows the capacity consumed, not the mass.

On a dedicated vehicle the question disappears entirely, because the whole vehicle is the unit. That is the difference our groupage article works through, and the reason a bulky light load sometimes costs less on a dedicated van than on a shared network.

How is sea freight different?

It compares a cubic metre against a tonne instead, which is a far more generous basis. Less-than-container-load sea freight is conventionally rated on whichever is greater of the volume in cubic metres and the weight in tonnes — a 1:1 comparison rather than air's 1:6.

Put the three side by side and the pattern is clear: the faster the mode, the harder it charges for space. Air treats a cubic metre as about 167 kg, express as 200 kg, and sea as 1,000 kg. Density decides which mode is economic long before transit time does.

That ordering is also why a consignment that is uneconomic by air is often fine by road or sea, and why the first question about a bulky shipment should be the mode rather than the carrier. Our air versus road freight comparison covers the trade.

How do you reduce chargeable weight?

By removing air, in four places. None of this is clever: it is the same discipline applied to each dimension of the stack.

1. Reduce the height, which is the dimension people over-provide. Every 10 centimetres off a 120 by 80 pallet removes 16 kg of volumetric weight at the 6,000 divisor.
2. Fill the footprint rather than stacking a narrow column in the middle of a pallet.
3. Consolidate, because two half-filled pallets are charged as two pallets.
4. Check whether it can be stacked, since a load marked non-stackable buys the space above it on a shared vehicle.

That last point is the expensive one and it is frequently applied by default. A consignment declared non-stackable without a reason is paying for headroom nobody is using.

What should you measure, and how?

The outside of what will actually travel, at its largest point, after it is packed. Three rules make the number match the carrier's.

1. Measure the widest and tallest point, including overhang, corner protection and shrink wrap.
2. Include the pallet in the height, not just the goods on it.
3. Measure each consignment separately where items differ, then total the volumetric weights rather than averaging the dimensions.

Then give the carrier the dimensions alongside the weight at the quoting stage. A quote based on weight alone is a provisional number, and the version that arrives on the invoice will have been recalculated from whatever the vehicle or the handling agent measured.

Why does the invoice differ from the quote?

Because the consignment gets measured again by somebody who is not you. A quote is calculated from the dimensions you supplied; the invoice is calculated from the dimensions recorded when the goods were handled, and where those disagree the handled figure wins.

Three things cause the gap, and all three are visible before dispatch. The stack grew: wrap, corner boards and a lid that was not in the original figure. The pallet was not counted. Or the goods were re-palletised into a larger footprint somewhere in the chain, which converts a 100 by 120 consignment into a 120 by 120 one without anybody intending it.

1. Record the dimensions at collection, in writing, as part of the job rather than afterwards.
2. Photograph the packed consignment beside something of known size.
3. Check whether it was re-palletised before accepting a re-measurement.

That record is the only thing that turns a re-measurement into a conversation instead of an invoice. Our proof of delivery article covers what the delivery record does and does not evidence, and the same discipline applies at the other end of the journey.

What is our part in this?

Most of our work is dedicated road vehicles, where the unit is the vehicle and the volumetric question does not arise — a van either takes the load or it does not. Our payload and gross vehicle weight article covers the limit that actually binds there, which is mass rather than space.

Where the movement is air freight, chargeable weight is how it is priced, and we ask for dimensions with the weight for exactly that reason. Our air freight page sets out that work and Heathrow cargo collections the ground leg of it.

For what decides the vehicle rather than the price, see kerbside delivery and who unloads and when your load is too big for a van; for consolidation, groupage.