Chargeable weight · IATA

Chargeable weight calculator

Enter cargo dimensions and actual weight per piece. The tool returns volumetric weight against the mode divisor (sea 1:1, air 1:6, courier 1:5), the chargeable weight (the larger), and the rounded billable weight per mode tariff.

Last updated 2026-05-08. Math runs in your browser, no data leaves your computer.

General guidance only, not legal or professional engineering advice. Verify against the cited primary sources (IMDG, REACH, ChAFTA, RCEP, Customs Tariff Act, supplier SDS, etc.) before committing to a shipment, declaration, or contract. Sourzi assumes no liability for outcomes based on these calculators.

Take the bounding-box dimensions including pallet, stretch wrap, and corner protectors. Carriers measure the bounding box, not the cargo silhouette. The chargeable weight is the larger of actual and volumetric weight.

Number of identical packages. Volumetric weight is computed per piece, then multiplied by pieces.

Gross weight per piece including pallet, packaging, and dunnage.

Why three different divisors

Each freight mode has its own marginal cost structure. A container ship loses no money on dense cargo; the limiting factor is the deadweight tonnage of the vessel and the lift capacity of port cranes. So sea freight prices on weight or measure (W/M) at a 1:1 ratio, billing the larger of metric tonnes and cubic metres. A 5-tonne crate that takes one cubic metre is billed at 5 W/M; a 1-tonne crate that takes 5 cubic metres is also billed at 5 W/M. Same revenue, very different cargo profile.

Air cargo is fundamentally constrained by aircraft cubic capacity rather than aircraft weight. A 747 freighter can lift 110 tonnes deadweight but only 700 m³ of cargo volume; the volume cap binds long before the weight cap on most freight loads. The IATA 1:6 ratio (167 kg per cubic metre) reflects the design of the aircraft hold; cargo at this density fills the aircraft to both caps simultaneously. Cargo at higher density is the airline good news (it pays per kilogram and uses less volume); cargo at lower density is priced up to the volumetric weight to cover the lost-revenue opportunity from the volume the airline cannot now sell.

Courier express networks (FedEx, DHL, UPS, TNT) operate trucks and small aircraft on dense urban routes. The economics are driven by the parcel-per-truck count, not the total weight; a truck full of feathered pillows is the same cost to drive as a truck full of bricks. The 1:5 ratio (200 kg per cubic metre) is tighter than air cargo because the network is volumetric throughput first, weight throughput second. Some express services tighten further to 1:4 (250 kg per cubic metre) for urban same-day delivery.

The practical implication: dense industrial chemical cargo (NaOH 50 percent, sulfuric acid, fine industrial powders) almost always quotes by actual weight regardless of mode. Lower-density cargo (insulation, packaging, low-density chemicals like activated carbon at 0.4 t/m³, or palletised paper bag goods) usually quotes by volumetric weight, especially on air or courier. Always run both numbers; whichever is larger is what the carrier bills.

Worked example. 1 pallet of palletised paper-bag goods

The booking. A buyer needs 1 pallet (1.20 m × 1.00 m × 1.50 m, 600 kg actual) of palletised 25-kg paper bags shipped urgent from Shanghai to Los Angeles. The buyer asks the freight forwarder for sea LCL, air cargo, and courier express options. Volumetric volume is 1.20 × 1.00 × 1.50 = 1.80 m³. Sea LCL: 1.80 m³ × 1,000 = 1,800 kg volumetric vs 600 kg actual; chargeable 1,800 kg, or in W/M terms 1.8 W/M. Air cargo IATA 1:6: 1.80 m³ × 167 = 301 kg volumetric vs 600 kg actual; chargeable 600 kg. Courier express 1:5: 1.80 m³ × 200 = 360 kg volumetric vs 600 kg actual; chargeable 600 kg. Looks fine on paper.

The failure. Buyer chooses sea LCL because it is "the cheapest mode" and quotes the rate at 75 USD per W/M, expecting 1.8 × 75 = 135 USD. Forwarder invoice arrives at 247.50 USD. The forwarder applied a 1.0 W/M minimum per shipment per BL plus a 1.30 m³ stuffing factor on a non-stackable pallet. Buyer is over by 113 USD. Then the buyer realises the air cargo would have been 600 kg at 4.50 USD per kg = 2,700 USD, twice the sea LCL even after the surcharge, but the air cargo would have arrived 21 days sooner. The 113 USD cost less than the 21 days of inventory delay, but the buyer had no easy way to make that comparison without itemising both modes.

The fix. On the next shipment the buyer runs the chargeable weight against all three modes at quote time, asks the forwarder for the actual W/M rate including any stuffing factors and minimums, and computes the all-in cost per piece per mode. The right answer for paperbag goods at 600 kg per pallet on a 14-day-tolerable timeline is sea LCL at 247.50 USD; the right answer for the same goods on a 5-day-required timeline is air cargo at 2,700 USD. The wrong answer is to lock in sea LCL because it sounded cheap and discover the surcharge after the fact.

Frequently asked

What is chargeable weight?

Chargeable weight is whichever is greater between the actual weight of the cargo and the volumetric (dimensional) weight, computed against a mode-specific divisor. Carriers price freight on chargeable weight, not actual weight, because dense cargo and bulky cargo each carry a marginal cost the other does not.

Why does air freight use 1 to 6 and courier use 1 to 5?

Air-cargo IATA standard is 1 cubic metre = 167 kg (one tonne per 6 m³, or the inverse 6 m³ per 1,000 kg). Courier (FedEx, DHL, UPS, TNT) uses a tighter 1 m³ = 200 kg (1 m³ per 5,000 kg) because their planes and vans carry smaller, lighter parcels and the volumetric throughput drives the network economics. Sea freight uses 1 m³ = 1,000 kg as a notional 1 to 1, since LCL ocean freight is conventionally priced per CBM or per W/M (whichever is greater).

For sea LCL, do I pay per kilogram or per cubic metre?

Per W/M, "weight or measure". The carrier or NVOCC quotes a W/M rate (e.g. 75 USD per W/M) and bills you per metric tonne or per cubic metre, whichever is greater. The 1:1 ratio of metric tonnes to cubic metres is the underlying convention. Dense cargo is priced by tonnes; bulky cargo is priced by CBM.

How is volumetric weight rounded?

Carriers round dimensions per their tariff. IATA air freight rounds the calculation result to the next half-kilogram (6.0 kg, 6.5 kg, 7.0 kg, etc) for shipments under 50 kg, and to the next whole kilogram above 50 kg. Courier rounds the result to the next whole kilogram. Ocean LCL rounds the W/M result to the nearest 0.001 metric tonne or 0.001 m³.

Where do I get the dimensions for irregular cargo?

Use the maximum bounding-box dimensions of the cargo, including any pallet base or packaging. Carriers measure the bounding box, not the cargo silhouette. For a drum on a pallet that is 1.20 m × 1.00 m × 1.30 m, the bounding box is 1.20 × 1.00 × 1.30 = 1.56 m³.

My freight forwarder quoted a different chargeable weight. Why?

Three common reasons. (1) The forwarder used a different volumetric divisor (some courier networks use 4,000 instead of 5,000 for express services). (2) The forwarder added pallet height or stretch wrap height to the cargo height. (3) Rounding was applied at a different stage of the calculation (per piece versus shipment total). Ask the forwarder for the exact divisor and the rounding step, in writing.

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