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Chargeable weight calculator

A free chargeable weight calculator online for air freight - enter every carton size on the packing list and see the weight the airline will actually invoice, with the arithmetic shown.

In the units selected above - cm³ per kg, or in³ per lb. Take it from your own quote or service guide; it is the one number on this page that is genuinely yours.

Size 1

Your quoted rate at this weight. Adding it turns the weight into a freight figure and unlocks the weight-break check below.

The next band up on your rate sheet - commonly 45, 100, 300, 500 or 1000 kg.

The lower per-kg rate that applies once you reach it.

Enter each carton size on the packing list, how many, and what one weighs. The chargeable weight appears here.

How this is calculated

Volumetric weight = total shipment volume ÷ divisor
Chargeable weight = the greater of volumetric weight and gross weight

Assessed on the whole consignment, not carton by carton, then rounded
up before it is rated. The divisor comes from the service you booked,
not from the cargo.

Assumptions

  • The divisor is yours to supply. Air freight, courier, road and LCL each work to a different ratio, they differ between forwarders, and they get revised. The presets here are the figures in common commercial circulation, not values read from a carrier's published tariff - IATA's TACT is a paid publication and every courier rate card checked is closed to automated access. Take your own number from your quote and use Custom.
  • Switching to inches and pounds converts the selected ratio exactly, so 6000 cm³/kg becomes 166.08 in³/lb. Carriers publish a rounded 166 or 139 instead. The difference is under one per cent, but if your rate sheet names a figure, enter it as a custom divisor rather than trusting the conversion.
  • Rounding up to the next half unit is the common air freight convention, not a universal rule. Some carriers round each dimension up before the divisor is applied as well, which this tool does not do - so the result is a floor, and a real air waybill can land slightly above it.
  • Dimensions are the outside measurements of the packed and palletised cargo. If your cartons are built onto a pallet, measure the pallet footprint and the full stacked height, and include the pallet's own weight in the gross.
  • Rate breaks, where entered, are compared on freight cost alone. Fuel, security, handling and airport charges are usually assessed on the chargeable weight too, so a break that saves on freight normally saves a little more once the surcharges follow it.

How to use this chargeable weight calculator

Enter one line for each carton size on your packing list: the three outside dimensions, how many pieces, and what one piece weighs. Add a line for every size - a real air shipment rarely has one. Pick the service you are being rated under, and the chargeable weight appears immediately, with the volumetric weight, the gross weight and the arithmetic that produced them printed underneath so you can check the figure line by line against a quote.

There is no calculate button. Change a dimension and the answer moves.

The whole shipment, not one carton at a time

This is the part almost every other calculator gets wrong by omission, and it is worth being precise about.

Chargeable weight is assessed on the consignment. You total the volume of everything, divide that one total by the divisor, and compare the result against the total gross weight. What you must not do is run each carton size through separately and add the answers together - that lets a dense carton be billed on its weight while a light carton beside it is billed on its volume, and the sum comes out higher than the airline’s own figure.

A single-box tool cannot do it any other way, so it pushes the user into exactly that mistake. Rows are the fix, and they are the reason this page exists.

Worked example: a two-size air shipment

Two sizes on the packing list, rated as air freight on a 6000 divisor:

  • 4 cartons at 60 x 40 x 40 cm, 13 kg each
  • 2 cartons at 55 x 45 x 40 cm, 15 kg each

Volume. 60 x 40 x 40 = 96,000 cm³ each, so four is 384,000 cm³. 55 x 45 x 40 = 99,000 cm³ each, so two is 198,000 cm³. Together that is 582,000 cm³, or 0.582 m³.

Volumetric weight. 582,000 ÷ 6000 = 97 kg.

Gross weight. (4 x 13) + (2 x 15) = 82 kg.

Chargeable weight. The greater of 97 and 82, so 97 kg. You are billed on volume, and you are paying for 15 kg the shipment does not have - 18 per cent more than it weighs.

Now look at what that costs. At a 4.60 per kg rate the freight is 97 x 4.60 = 446.20. But the rate sheet has a band at 100 kg where the rate drops to 4.05, and 100 x 4.05 = 405.00. Declaring three kilograms you do not have saves 41.20, about nine per cent, and no other calculator on the first page of results will tell you that.

Rounding, and why the airline’s number is higher than yours

Airlines rate in steps, usually the next half kilogram. A shipment computing to 97.2 kg is rated at 97.5 kg. The step is small and it always rounds against the shipper, so it belongs in the calculation rather than as a footnote.

Many carriers also round each individual dimension up to the next whole centimetre before applying the divisor. This tool deliberately does not - it uses your figures exactly as typed, so the number you see here is a floor. If your cartons measure 60.4 cm on a side, expect the air waybill to be built on 61.

Chargeable weight for US and UK shipments

The arithmetic is identical either side of the Atlantic; only the units and the ratio move. Switch the tool to inches and pounds and it converts the selected ratio exactly, so the 6000 cm³/kg air freight standard becomes 166.08 in³/lb. US rate sheets usually print a rounded 166 for air freight and 139 for express courier, and UK and European paperwork almost always stays in centimetres and kilograms.

The difference between 166.08 and 166 is under one per cent, but if your rate sheet names a number, enter it as a custom divisor. A divisor from the wrong unit system is not a rounding error - a cm/kg divisor applied to inches is wrong by a factor of roughly twenty-seven, which is the single most expensive mistake available on this page.

What this does not include

The chargeable weight is the basis for the freight charge, not the invoice total. Fuel and security surcharges, airport handling, customs clearance, screening and delivery all sit on top, and several of them are themselves assessed per chargeable kilogram. To take the number further, the shipping cost per unit calculator turns a freight total into a per-item cost, and the landed cost calculator adds duty and tax on top of that.

If you only need the volumetric figure for a single parcel rather than a whole consignment, the volumetric weight calculator is the shorter route to it.

Frequently asked questions

What is a chargeable weight calculator?
It is a tool that works out which of two weights an airline or forwarder will bill you on - the weight your shipment actually is, or the weight its size implies. Carriers charge on whichever is greater, so a light bulky consignment is rated on the space it fills rather than what the scales say. This one takes a full packing list rather than a single box, because chargeable weight is assessed on the whole consignment.
How do I calculate chargeable weight?
Total the volume of every carton, divide that total by your carrier's divisor to get the volumetric weight, then take whichever is greater - that figure or the gross weight. For a shipment measuring 582,000 cm³ with an air freight divisor of 6000, the volumetric weight is 97 kg. If the same shipment weighs 82 kg on the scales, you are billed on 97 kg.
Is chargeable weight worked out per carton or for the whole shipment?
For the whole shipment. Total the volume first, divide once, then compare against the total gross weight. Comparing each carton separately and adding the winners together gives a higher and wrong answer on any mixed load, because it lets a dense carton be billed on its weight while a light one beside it is billed on its volume. That is the error a single-box calculator quietly pushes you into.
Why divide by 6000 for air freight volumetric weight?
A divisor is an assumed density written as a division. Dividing cubic centimetres by 6000 says one cubic metre of hold space is worth about 167 kg of revenue, because 1,000,000 ÷ 6000 = 166.67. Air freight settled on that ratio commercially rather than physically, which is why express courier services use 5000 instead and rate the same carton as heavier.
Why is 1 CBM 167 kg?
Because 1 cubic metre is 1,000,000 cm³ and the air freight divisor is 6000, so 1,000,000 ÷ 6000 = 166.67 kg, which rounds to 167. It is not a physical density - it is the ratio air freight uses to convert space into billable weight. On an express courier divisor of 5000 the same cubic metre bills as 200 kg instead.
How much is 1 CBM in air freight?
One cubic metre is charged as roughly 167 kg on the standard air freight ratio, so it costs 167 multiplied by your per-kg rate. At 4.60 per kg that is about 767 per cubic metre. Change the divisor and the answer changes with it, which is why the tool prints the figure it used rather than assuming one.
How many CBM is 1 kg?
Turning the air freight ratio round, 1 kg of chargeable weight buys about 0.006 m³, since 1 ÷ 166.67 = 0.006. Put another way, 6000 cm³ of space bills as one kilogram. That is the same statement as the divisor, read from the other end.
How much is 1000 kg in CBM?
If 1000 kg is chargeable weight on the air freight ratio, it corresponds to about 6 m³, because 1000 ÷ 166.67 = 6. That does not mean your cargo occupies 6 m³ - it means 6 m³ is the volume at which volume and weight would bill the same. Below that volume you are billed on weight, above it on volume.
How much is 3 CBM in kg?
On the air freight ratio, 3 m³ bills as about 500 kg, because 3 × 166.67 = 500. On an express courier divisor of 5000 the same 3 m³ bills as 600 kg. Neither figure is what the cargo weighs; both are what you would pay for if volume is the binding constraint.
How do I convert CBM to tons?
For sea LCL the convention is that 1 m³ counts as 1000 kg, so cubic metres and metric tons map one to one and you are billed on whichever is greater. That figure is called the revenue ton or freight ton. Air freight does not use it - a cubic metre there is about 167 kg, six times lighter - so do not carry a sea ratio onto an air quote.
Is 1 cubic metre a ton?
In sea freight, by convention, yes - LCL bills 1 m³ as 1000 kg, which is one metric ton. Physically it depends entirely on what is in it, since a cubic metre of water is a ton and a cubic metre of polystyrene is a few kilograms. In air freight it is emphatically not - one cubic metre is treated as about 167 kg.
Why is my chargeable weight rounded up?
Airlines rate in fixed steps, most commonly the next half kilogram, so a shipment computing to 97.2 kg is rated at 97.5 kg. The step is small but it always moves against you, and it is applied after the volumetric comparison, not before it. You can switch the rounding off in the tool to see the unrounded figure underneath.
Can it be cheaper to declare a higher weight?
Yes, and this is the most useful thing on the page. Air freight is rated in bands - a rate up to 45 kg, a lower one over 45, lower again over 100, 300, 500 and 1000 - so a shipment just under a band pays a high rate on all of it. At 97 kg and 4.60 per kg the freight is 446.20, while declaring 100 kg at the 4.05 band rate is 405.00. Buying 3 kg you do not have saves 41.20. Enter your two rates and the tool checks it for you.
Is chargeable weight the same as volumetric weight?
No. Volumetric weight is one of the two inputs; chargeable weight is the answer. Volumetric weight converts your shipment's size into a weight, and the chargeable weight is whichever is greater once you compare it against the gross. If you only want the volumetric figure for a single parcel, the volumetric weight calculator is the simpler page for it.

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Sources & methodology

This calculator uses only definitional arithmetic - no carrier-specific or regulatory constants - so there is nothing external to cite.

Last updated

Results are estimates for planning purposes. Verify with your carrier or customs broker before committing. This is not professional advice - see the disclaimer.

Every calculation runs in your browser. Nothing you type is sent to a server or stored anywhere.