Chargeable Weight Calculator for Air Freight

Worked example

Two pieces, each 100 × 80 × 60 centimeters, each weighing 50 kilograms.

One piece is 480,000 cm³. Divided by 6,000 that is 80 kg volumetric.
Two pieces: 160 kg volumetric against 100 kg actual.
The greater figure wins, so you are billed on 160 kilograms.

You are paying for 60 kilograms of air. Getting each piece down to 90 × 70 × 55 cm would bring the volumetric weight to 115.5 kg and cut the bill by more than a quarter, without removing a single item.

The formula

Volumetric per piece = L × W × H (cm) ÷ 6,000
Volumetric total     = volumetric per piece × pieces
Actual total         = weight per piece × pieces
Chargeable           = greater of the two,
                       rounded UP to the next 0.5 kg

Why 6000 and not 5000

The divisor is a statement about what the carrier is really selling. At 6,000 cm³ per kilogram, one cubic meter bills as 166.7 kg. At 5,000 the same cubic meter bills as 200 kg.

General air cargo booked through a freight forwarder normally uses 6,000, which is the IATA standard. Express courier products, including DHL Express, use 5,000, which produces a heavier billable weight for the same box. When you compare an air quote against a courier quote, check which divisor each one is using before you decide the courier is more expensive.

Where air freight costs are decided

Air rates step down as chargeable weight rises, in bands that are usually something like under 45 kg, then 45, 100, 300, 500 and 1000 kg. The rate per kilo falls at each break.

That creates a useful quirk: it is sometimes cheaper to ship a heavier consignment. If you are at 95 kg chargeable and the next band starts at 100, the 100 kg rate applied to 100 kg can total less than the higher rate applied to your 95. Forwarders will normally spot this and quote the lower figure, but not always, and it is worth asking when you are just under a break.

It also changes how you consolidate. Two 60 kg shipments sent separately are billed at the under-100 rate twice; combined into one 120 kg consignment they clear the 100 kg break and are billed once, at a lower rate per kilo, with one set of fixed charges instead of two.

Common mistakes

Measuring the contents. The carrier measures the packed piece, including the pallet, the strapping and any bulge in the sides.
Averaging across pieces. Measure each piece and add them up. One oversized piece among small ones changes the total.
Rounding before the comparison. Compare the true volumetric and actual figures first, then round the winner up to the next half kilo.
Assuming the courier divisor. Using 5,000 when your forwarder bills at 6,000 overstates your cost by 20%.
Ignoring the shape of the box. A long thin piece can also hit oversize handling rules on top of its volumetric weight.

FAQ

What is chargeable weight?

The greater of your shipment actual weight and its volumetric weight. Air carriers sell space as much as lift, so a light bulky shipment is billed on the room it takes.

What divisor does air freight use?

The IATA standard is 6000 cubic centimeters per kilogram. Multiply length by width by height in centimeters and divide by 6000 to get volumetric weight in kilograms.

How is chargeable weight rounded?

Up to the next half kilogram. A shipment at 4.8 kg bills at 5.0 kg, and one at 5.1 kg bills at 5.5 kg.

Why is air freight 6000 when couriers use 5000?

They are different products. General air cargo through a freight forwarder normally uses 6000, while express courier services such as DHL Express use 5000, which produces a higher billable weight for the same box.

Do I measure each piece or the whole shipment?

Each piece, then add them up. Measure the outside of the packed piece at its widest points, including any bulges or strapping.

Rules last checked: Sep 24, 2026

Estimate only. Confirm with your carrier before booking.