What is chargeable weight?

Chargeable weight is the figure a carrier actually bills — the greater of a shipment's real weight and the weight equivalent of the space it occupies. Light, bulky cargo is billed on its space so it doesn't ship almost free by weight; dense cargo is billed on its weight. How space is measured differs between air and ocean.

How do you calculate dimensional weight for air freight?

Volumetric (dimensional) weight for air = total volume ÷ a dimensional divisor. The IATA standard is 6000 cm³/kg (metric) or 166 in³/lb (imperial); express carriers often use 5000 or 139. The chargeable weight is the greater of actual and volumetric, rounded up to the next half kilo. A shipment of 0.96 m³ at the 6000 divisor has a 160 kg volumetric weight.

Why do express carriers use a 5000 divisor instead of 6000?

A smaller divisor produces a larger volumetric weight, so it charges more for the same box. The IATA standard is 6000 cm³/kg, but many express and courier services use 5000 (or 139 in imperial). The same 0.96 m³ shipment is 160 kg at 6000 but 192 kg at 5000 — always confirm which divisor your carrier applies.

Chargeable Weight: Air vs Ocean

Q: What is a revenue ton in ocean freight?

For ocean LCL, freight is billed in revenue tons on a weight-or-measurement (W/M) basis: one revenue ton is the greater of the volume in cubic metres (CBM) and the weight in metric tonnes. A 0.96 CBM, 80 kg shipment bills as 0.96 revenue tons, because the volume exceeds the 0.08-tonne weight.

Carriers bill the greater of what a shipment weighs and the space it fills — so light, bulky cargo doesn’t ship almost free. How the space is measured differs by mode: air uses volumetric weight (volume ÷ a divisor), ocean LCL uses revenue tons (the greater of CBM and tonnes). Here’s each, worked on the same shipment.

Why chargeable weight exists

A pallet of pillows and a pallet of bricks take the same floor space but weigh worlds apart. If carriers billed on weight alone, the pillows would ride almost free while eating the same room in the aircraft or container. So they bill the greater of actual weight and a space-based weight. Whether weight or space wins depends on your cargo’s density — and the threshold is different for air and ocean.

Air: volumetric (dimensional) weight

Volumetric weight = total volume ÷ dimensional divisor. The IATA standard divisor is 6000 cm³/kg (or 166 in³/lb); express carriers often use 5000 (or 139), which bills more for the same box. The chargeable weight is the greater of actual and volumetric, rounded up to the next half kilo. Below roughly 167 kg per cubic metre, volume wins.

Ocean LCL: revenue tons

Ocean LCL bills in revenue tons on a weight-or-measurement (W/M) basis: one revenue ton is the greater of the volume in cubic metres (CBM) and the weight in metric tonnes. The break-even is 1,000 kg per cubic metre — so most LCL freight, which is lighter than a tonne per CBM, bills on measurement (volume).

The same shipment, both ways

Ten cartons at 60×40×40 cm each — 0.96 m³ total — weighing 80 kg:

Mode / basis	Actual	Billed on
Air — divisor 6000	80 kg	160 kg (volumetric)
Air — divisor 5000 (express)	80 kg	192 kg (volumetric)
Ocean LCL — W/M	80 kg	0.96 revenue tons (measurement)

At 80 kg of actual weight, every option bills on space: air charges you for 160–192 kg, and ocean for nearly a full revenue ton. Flip to a dense shipment — five cartons at 40×30×30 cm, 200 kg — and it reverses: air bills the full 200 kg actual (its volumetric is only 30 kg) and ocean bills on the 0.20-tonne weight, not the 0.18 CBM.

You’re not billed for what your freight weighs. You’re billed for whichever costs the carrier more — the weight or the room.

What to do about it

Two moves. Measure honestly — to the farthest points, packaging and pallet included, because that’s what the carrier measures. And tighten the pack — less void space lowers volumetric weight on light cargo and can move you to a cheaper basis. When you’re choosing between modes or filling a box, pair this with the container load calculator to see whether volume or weight fills first, and build the whole cost into your landed cost.