QUICK ANSWER Chargeable weight is the number an airline actually bills: the greater of your shipment's gross weight and its volumetric weight, where volumetric weight in air freight is length x width x height in centimeters divided by 6,000. One cubic meter therefore "weighs" about 167 kg for billing purposes. Dense cargo pays by the scale; light, bulky cargo pays by the tape measure.
Every chargeable weight question on an air quote comes down to one thing: is your cargo heavy or big? A plane runs out of space faster than it runs out of lifting power, so pricing charges whichever constraint your shipment consumes more of. Here is the chargeable weight formula, three worked examples, and the rate mechanics that follow from it.
Two weights, one bill
Every air freight shipment carries two weights. Gross weight is what the scale says, cargo plus packaging. Volumetric weight converts the space the shipment occupies into a billing equivalent, using the volume math covered in our CBM guide. The airline compares the two and bills the larger, and that larger number is the chargeable weight on your air waybill. Feathers and machine parts can occupy the same pallet position; the formula exists so they do not pay the same price for it.
The formula: divide by 6,000
In metric, volumetric weight in kilograms is length x width x height in centimeters, divided by 6,000. Working in inches, divide the cubic inches by 366 to get kilograms. The equivalence to remember: one cubic meter comes out at roughly 167 kg. A shipment of 2 CBM and 180 kg gross works out to 333.3 kg volumetric, billed as 333.5 after rounding, so the tape measure, not the scale, sets that invoice. Most airlines then round the chargeable weight up to the next half kilogram, and rates below the minimum charge get bumped to the minimum regardless of the math.
Three shipments, worked through
Chargeable weight in practice
| Shipment | Gross weight | Dimensions and volumetric | Chargeable |
|---|---|---|---|
| 4 cartons of machine parts | 380 kg | 0.9 CBM = 150 kg volumetric | 380 kg (gross wins) |
| 10 cartons of down jackets | 120 kg | 2.4 CBM = 400 kg volumetric | 400 kg (volume wins) |
| Mixed: parts + jackets together | 500 kg | 3.3 CBM = 550 kg volumetric | 550 kg (totals compared, not per carton) |
The third row carries the practical lesson: chargeable weight is compared at shipment level, so dense and bulky cargo booked together partially offset each other. Two suppliers shipping separately can pay more than the same cargo consolidated on one air waybill.
One concept, four divisors
The same box, weighed four ways
| Mode | Divisor and equivalence | What it means |
|---|---|---|
| Air freight | cm3 / 6,000, about 167 kg per CBM | The IATA standard this guide covers |
| Express courier | cm3 / 5,000, about 200 kg per CBM | Integrators bill volume more aggressively |
| Domestic parcel (DIM) | cubic inches / 139 for pounds | Parcel networks, different world entirely |
| Ocean LCL (W/M) | 1 CBM against 1,000 kg | Ocean bills volume OR weight per revenue ton |
TAKEAWAY The same carton has a different billing weight in every network it touches. When comparing air, courier, and ocean quotes, convert each to its own chargeable basis first; comparing scale weight across modes is how bulky cargo ends up on the wrong one.
Rate breakpoints: when more weight costs less
Air freight rates come in weight slabs: a minimum charge, then per-kilogram prices at under 45 kg, and cheaper tiers above 45, 100, 300, 500, and 1,000 kg. The per-kg rate falls as the slab rises, which produces the trade's small arithmetic trick: near a breakpoint, declaring the higher weight can cost less. A 280 kg chargeable shipment priced at the plus-100 rate can total more than the same shipment billed "as agreed" at 300 kg on the plus-300 rate. Any forwarder quoting seriously runs this check; what the current per-kg levels look like belongs to our air freight cost guide.
Packing the chargeable weight down
Because the tape measure sets the bill for light cargo, packaging is a pricing tool. Cartons sized to the product rather than to the supplier's standard box cut dead air that bills at 167 kg per CBM. Compression packing matters for textiles; master cartons beat many small boxes; and a rebuilt pallet that loses five centimeters of height loses real money's worth of volumetric weight across a year of shipments. For FBA-bound goods, prep done before the air leg means the wasted carton space never flies; prep done after means you paid air rates to move it.
How Platton quotes chargeable weight
Chargeable weight disputes are almost always surprise disputes, and the fix is showing the math before anything flies.
Both weights on the quote, not just the bill
A Platton air freight quote states gross, volumetric, and the chargeable result per shipment, from the packing list dimensions, so the number on the invoice is the number you approved.
Breakpoint checked before booking
Every air quote near a slab boundary gets the as-agreed comparison run both ways. When 300 kg prices below 280, the quote says so.
Dense and bulky booked together
Dense and bulky cargo from the same origin week gets reviewed for one-AWB consolidation, because offsetting weights on a single air waybill is the cheapest chargeable-weight optimization there is.
Get an air quote with the chargeable weight shown
Common Questions About Chargeable Weight
Why does air freight divide by 6,000?
The divisor encodes an assumed density: 6,000 cubic centimeters per kilogram, or about 167 kg per cubic meter. Cargo denser than that pays by weight, lighter pays by volume, and the airline's revenue stays tied to whichever resource, payload or space, the shipment actually consumes. The 6,000 divisor is the IATA standard the industry settled on.
How many kilograms is 1 CBM in air freight?
About 167 kg. One cubic meter is 1,000,000 cubic centimeters, divided by 6,000 gives 166.7. That equivalence lets you estimate quickly from a packing list: total CBM times 167, compared against gross weight, and the larger number is what the rate multiplies.
What is the difference between gross, volumetric, and chargeable weight?
Gross is scale weight including packaging. Volumetric is the space converted to kilograms by the divisor. Chargeable is whichever of the two is greater, per shipment, and it is the only one of the three the rate multiplies. All three appear on a proper quote, which is how you check the math.
How do I calculate chargeable weight in inches?
Multiply length x width x height in inches, divide by 366, and you have volumetric kilograms; divide by 166 instead if you want pounds. Then compare against the gross weight in the same unit and take the larger. The metric and imperial routes land on the same answer within rounding.
Do airlines round chargeable weight up?
Yes, customarily to the next half kilogram, and every shipment is subject to a minimum charge regardless of how small the math comes out. On large shipments the rounding is noise; on small ones the minimum charge is often the real price, which is one reason very small air shipments gravitate to couriers.
Is courier volumetric weight the same as air freight?
Same idea, harsher divisor. Express integrators commonly divide by 5,000, taxing volume at about 200 kg per CBM against air freight's 167. A bulky shipment that is marginal on an air freight quote gets noticeably worse on a courier one, which is worth checking before defaulting to the express account.
Related Air Freight Guides
Air freight cost: what drives the price: the per-kg rates your chargeable weight multiplies.
Air vs ocean freight: the mode decision the chargeable math feeds.
What is CBM: the volume calculation underneath the divisor.
Air freight transit times: what the speed you are paying for looks like in practice.
