Which figure gets invoiced.
The logic is the same in every mode: chargeable weight is the greater of gross weight and volumetric weight. Only the divisor changes — and there is a critical distinction here. In air cargo the divisor of 6,000 is published by IATA. In road freight there is no universal coefficient: one corporate group publishes 333 kg/m³ in Belgium and 250 kg/m³ in Germany. That is a 33% difference.
Calculate
Pick the mode, enter the dimensions and the gross weight. Everything runs in your browser. Air cargo applies the TACT rounding rules — edges to the nearest whole centimetre first, the result up to the next half kilogram. The road coefficient field arrives empty, because no verified standard exists; you enter your own from your contract.
The divisors and who publishes them
The most important column in the table below is who publishes it. These coefficients circulate in the trade as "standards"; only one is genuinely an institutional publication.
| Mode | Divisor | kg / m³ | Published by | Binding |
|---|---|---|---|---|
| Air cargo | 6,000 cm³/kg | 166.667 | IATA | Industry default — has exceptions and carrier deviation |
| Express courier | 5,000 cm³/kg | 200 | The carrier's own service guide | No — varies by carrier |
| Sea LCL | — | 1,000 | The carrier's own tariff | No — a counter-example is published |
| Road groupage | — | 200 · 250 · 333 | Varies by carrier | No standard exists |
Even the 6,000 in air cargo is an industry default rather than a binding rule — TACT carries its own exceptions and a section permitting carrier deviation. The others are carrier tariffs outright.
A common error: multiplying by 167 kg/m³. The exact equivalent of the 6,000 divisor is 166.667 kg/m³. Using 167 overstates the result by about 0.2% — 33 kg on 100 m³. 167 is not an IATA figure; it is a convenience rounding. Do the calculation by dividing by 6,000.
Why road freight has no standard
This is the most widely misunderstood part of the subject. Many sources state that "1 LDM = 1,850 kg is the European standard" or that "1 m³ = 333 kg in road freight". No directive, EN or ISO norm, or institution publishing those coefficients could be found.
What was found is that these are carriers' own tariffs, and they diverge sharply. Two national companies of the same international group:
- Belgian company
- 1 m³ = 333 kg · 1 loading metre = 1,850 kg — and the same paragraph states the coefficient can be varied by contract
- German company (domestic)
- 1 m³ = 250 kg · 1 loading metre = 1,250 kg; no figure at all is given for international traffic
That is a gap of 33% to 48%. Another major operator states plainly on its own site that the conversion key varies by carrier and tariff, typically 333, 250 or 200 kg/m³.
The 2.40 m divisor in the loading-metre formula is not a physical measurement either. It is a billing convention — the actual internal width of a German standard semi-trailer is 2.48 m. The widely quoted 1,750 kg/LDM does not come from a norm but from dividing a semi-trailer's roughly 24-tonne payload by 13.62 loading metres.
When taking a road quotation, ask for the coefficient and get it in writing. "Volumetric weight applies" is not enough; the kg/m³ and kg/LDM figures must be stated. The same cargo is invoiced 33% differently at 333 kg/m³ than at 250 kg/m³.
Ask about the rounding step too. Most groupage carriers round the loading metre up to the next 0.1 or 1.0, and that step is nowhere standardised.
Settle stackability up front. If your cargo cannot be stacked the calculation runs on loading metres rather than cubic metres and the cost changes materially. With some carriers dangerous goods are always treated as non-stackable on safety grounds.
Air cargo rounding rules
Air cargo is the only mode whose coefficient is published institutionally — but the calculation itself has rules too, and most calculators skip them.
- Dimensions are rounded first. Each edge to the nearest whole centimetre: 0.5 and above up, 0.4 and below down. 11.3 cm → 11 cm. This is not an "always round up" rule.
- Dimensions are external. The greatest length, greatest width and greatest height — including protrusions, tape, packaging and pallet overhang.
- Volumetric weight is computed to three decimals, then rounded.
- Kilogram rounding is in half-kilogram steps. A fraction of 0.51–0.99 goes to the next whole kilogram; exactly 0.5 stays; 0.1–0.4 goes to the next half kilogram. Examples: 25.665 → 26.0 · 36.5 → 36.5 · 88.358 → 88.5.
- On a multi-piece consignment each piece is computed and rounded separately, then summed. Adding the volumes and dividing once gives a wrong answer.
Worked example: 162.2 × 155.6 × 141.4 cm → rounded 162 × 156 × 141 → 3,563,352 cm³ → divided by 6,000 = 593.892 → 594.0 kg.
6,000 is not absolute. Published exceptions exist: a divisor of 7,000 applies for certain origins and commodities. Carriers may also deviate from TACT rates through their own bulletins — one Turkish carrier's bulletin states plainly that TACT rates may not be used even where they are lower than the bulletin rates.
W/M and the revenue ton at sea
On less-than-container-load sea freight, quotations carry the abbreviation W/M: weight or measurement. Freight is calculated on whichever of gross weight and volume produces the greater revenue for the carrier.
The chargeable unit — the revenue ton — is the greater of gross weight in tonnes and volume in cubic metres. The threshold is therefore 1,000 kg/m³: denser than that and you are billed on weight, lighter and you are billed on volume.
But this is not a binding standard. Several carriers publish that provision in their own tariffs — and a published counter-example exists: one NVOCC tariff defines the same unit as 800 pounds. Decimal precision varies too; one carrier computes package volume to six decimals and rounds the total to two, another to three. There is no common standard.
The CBM calculation itself is consistent: the product of the three extreme dimensions, including protrusions, with a 0.5 cm rounding threshold.
My figure was right, the invoice was not
The most common question. Even a correct calculation can differ from the invoice, for these reasons:
- Minimum charge
- On small consignments, if the calculated amount falls below the minimum charge, the minimum applies. The effect is to change the unit cost entirely on small shipments.
- Weight break
- In air cargo, if calculating at the lower limit of the next weight band is cheaper, that applies and the invoiced weight becomes that lower limit. If 1,000 kg at the higher band rate is cheaper than 995 kg at the lower band rate, you are invoiced for 1,000 kg — for 5 kg you are not carrying.
- Stackability loss and contamination
- In road freight, if the cargo occupies more space than the standard calculation assumes, the loading metres actually required are invoiced. And with some carriers, if a single piece requires calculation on loading metres, the whole consignment moves to LDM.
- Rounding
- Different in every mode and mostly unstandardised. Groupage carriers' LDM rounding steps vary between carriers.
- Packaging included in the measurement
- Measurement is taken over the outer packaging, pallet overhang and protrusions. Calculating from the product's own dimensions always understates.
When it goes wrong
The coefficient is not asked for on a road quotation
"Volumetric weight applies" is accepted at face value. The invoice arrives calculated at 333 kg/m³ while the budget assumed 250 — a 33% gap.
Do this: require the kg/m³ and kg/LDM figures in the quotation, in writing.
Volumes are summed on a multi-piece air shipment
The volumes of differently sized pieces are added and divided once. The correct method is to compute and round each piece separately and then sum; the two give different answers.
Multiplying by 167
The exact equivalent of the 6,000 divisor is 166.667 kg/m³. Using 167 introduces a 0.2% upward bias that becomes visible on large volumes.
Calculating from the product's dimensions
Measurement covers outer packaging, pallet overhang and protrusions. A figure taken from the product carton always comes out low.
Air cargo and express divisors confused
Air cargo uses 6,000, express courier 5,000. A 60 × 50 × 40 cm carton with a gross weight of 15 kg is charged at 20.0 kg in air cargo and 24.0 kg in express — a 20% difference. The right divisor depends on the regime the goods move under, not on the carrier's name.
Frequently asked
How many kg is 1 m³ in road freight?
There is no single correct answer. Published values range between 200, 250 and 333 kg/m³ and all of them are carriers' own tariffs.
Some sources describe these as a "European standard", but no such directive, EN or ISO norm could be found. Take your own coefficient from your contract of carriage.
How is LDM calculated?
The common formula divides the cargo's footprint (length × width) by 2.40 and multiplies by the number of pieces. Stackable cargo is then divided by a stacking factor.
One Euro pallet (1.20 × 0.80 m) works out at 0.40 LDM on that formula — six Euro pallets correspond to 2.40 loading metres.
The 2.40 divisor is not the physical internal width, it is a billing convention; the real internal width is greater. The rounding step also varies by carrier.
Are air cargo dimensions always rounded up?
No — a common misconception. Each edge is rounded to the nearest whole centimetre: 0.5 and above up, 0.4 and below down. 11.3 cm becomes 11 cm.
Rounding up comes in at the kilogram step, and even there it is in half-kilogram increments. In the express regime the rules differ again and vary by carrier.
Is LCL freight always rounded up to a whole m³?
None of the carrier tariffs examined contained a rule rounding the revenue ton up to a whole number. Tariffs round the centimetre measurement and the CBM decimal, and set a minimum.
So the claim that it is "always rounded up to a whole cubic metre" could not be verified. Ask your own carrier what its tariff says about rounding.
Does this give me a price?
No. The calculator finds the chargeable weight only. Unit rates, minimum charges, weight bands and surcharges live in your carrier's tariff, and no tariff figures are embedded in this page.
If you would like a price for your shipment, send us the dimensions and weights.
Sources
- IATA — Volumetric weight calculation Dividing the consignment's volume in cubic centimetres by 6,000, and using whichever of volumetric and actual weight is higher · iata.org · accessed 1 Sep 2026
- Korean Air Cargo — Tariff and volumetric weight rules 6,000 cm³ = 1.0 kg; chargeable weight as the higher of actual and volume weight; imperial equivalents · cargo.koreanair.com · accessed 1 Sep 2026
- 96/53/EC — Maximum dimensions and weights of road vehicles What is binding are the external dimensions: articulated vehicle 16.50 m, road train 18.75 m, width 2.55 m. Internal width and the LDM divisor are not regulated by this directive · eur-lex.europa.eu · accessed 1 Sep 2026
This page is for information only. Apart from the 6,000 divisor in air cargo, none of these coefficients is a binding standard; they are commercial values carriers publish in their own tariffs and they change by contract. No universal coefficient could be found for road freight — which is why that field in the calculator arrives empty. The calculator does not give a price, only the chargeable weight, and no tariff figures are embedded. Verify your own coefficient and rounding rule against your contract of carriage and your carrier's tariff.
Change log
- Page and calculator published. Coefficients verified against primary sources; no institutional publisher could be found for road freight, so no fixed coefficient was embedded for that mode. Air cargo rounding follows the TACT rules.