Drums · IBC

Drum and IBC palletising calculator

Know the real drum count before you book the box.

A 20FT booked on a volume guess that ignores the payload limit either ships half-empty (you pay for air) or gets rejected at the terminal for overweight. Drums and IBCs almost always hit the weight cap before the floor area fills, and the binding dimension is rarely the one the quote assumed.

Pick the cargo unit (steel drum, plastic drum, IBC, big bag) and the container type.

Last updated 2026-05-09. Math runs in your browser, no data leaves your computer.

Choosing a preset fills the length, width, height, unit mass, and max stack below from the standard build for that unit. Override any field for your actual drum or IBC.

The internal floor, height, and payload come from the data plate for this container type. Confirm against the real box's plate before final loading, since tare and payload vary by build.

The five fields below prefill from the preset. Unit mass is the gross weight, liquid plus packaging; max stack is how many tiers the unit takes loaded, two for most drums and IBCs, one for big bags and bagged pallets.

General guidance only. Verify against the cited primary sources before you commit to a shipment, declaration, or contract.

Floor area, height, and payload

Container fit is the smaller of three constraints. Floor area: how many units fit in the container floor footprint, computed as floor length / unit length times floor width / unit width, rounded down. Height stack: container internal height / unit height, rounded down, capped at the unit max stack tiers (drums max 2, IBCs typically 2, big bags typically 1, pallets of bags 1). Payload: max gross cargo weight (28,000 to 28,600 kg in a typical box) divided by unit mass.

For dense chemical liquid cargo, the payload constraint binds first. A 20GP filled with 1000 L IBCs of NaOH 50% (1.5 SG) maxes out at about 18 IBCs (18,800 kg cargo + 1,200 kg IBC tare = 20,000 kg, well under the 28-tonne cap). Adding a 19th IBC pushes 19,800 kg of cargo, still fits the box but stresses the floor loading and the carrier handling. Most operators stop at 18 to 20 IBCs per 20GP.

For low-density cargo (paper bags, light powders, big bags of light material), the floor + height constraint binds first. A 20GP filled with 1 MT bags of activated carbon (0.4 SG) cubes out before it weighs out. This is where the height-stacking economics of 40HC vs 40GP matter; 40HC adds 30 cm of vertical room for 11 m^3 more cargo at the same freight rate.

A worked example

You book a 20GP of caustic soda 50% in 1000 L IBCs and size it on cube. The floor takes 10 IBCs and they stack two high, so on paper the box holds 20.

It doesn't. At SG 1.5 each filled IBC grosses about 1,565 kg, so 20 of them is 31,300 kg against the 20GP's 28,180 kg payload cap. The box weighs out at 18 IBCs and the terminal rejects the overweight booking. Dense liquid almost always hits the payload limit before the floor fills. The fix is to count by weight, not by deck space.

Run the same parcel and the payload binds at 18 IBCs, 28,170 kg, just under the cap, with the floor only 90% used. You book one 20GP for 18 IBCs and a second box for the balance, and both load clean.

Not sure which box gives the cheapest fit for this cargo? The container types reference lists the internal floor, height, and payload of every type at /tools/containers-and-logistics/container-types-reference.

Left with a part-load that won't fill a second box? The LCL versus FCL breakeven tool tells you when to consolidate instead at /tools/pricing-and-quoting/lcl-vs-fcl-breakeven.

Frequently asked

How many drums fit in a 20GP?

200 L drums in a 20GP: industry-standard hexagonal packing fits 40 drums per tier (10 long x 4 across; 200 L drum is ~590 mm OD so 10 x 590 = 5,900 mm matches the 5,898 mm container length almost exactly; 4 x 590 = 2,360 mm just inside the 2,352 mm internal width with shim allowance). At 2 tiers that is 80 drums, weighing roughly 20 tonnes at 250 kg gross each, comfortably under the 28-tonne payload cap. NOTE: the rectangular-packing math used by this calculator is CONSERVATIVE; cylindrical drums in real-world hexagonal arrangement fit slightly more than the rectangle-fit count returned.

How many IBCs fit in a 20GP?

1000 L IBCs in a 20GP: 10 IBCs single tier is the standard industry figure (1,200 x 1,000 mm footprint x 10 IBCs = 12 m^2 vs 13.87 m^2 floor area). Two-tier stacking (where IBCs are stackable) brings the practical fit to 18 to 20 IBCs; dense liquids weight-out before they cube-out so 18 to 20 IBCs maxes out the 28-tonne payload cap for SG ~1.5 cargo. Two-tier IBC loading is common for lower-density liquids and rare for caustic / sulfuric / dense aqueous.

How does palletising change the math?

Palletised cargo (paper bags on Euro 1.2 x 0.8 m or US 1.2 x 1.0 m pallets) loads by pallet count, not by individual bag. 10 Euro pallets fit a 20GP at 1.2 m square footprint; 9 to 10 US pallets fit at 1.2 x 1.0 m. Each pallet carries 1 MT of bagged product (40 x 25 kg bags, 1,000 kg per pallet); 10 pallets give 10 tonnes net cargo per 20GP.

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