Mixed load calculator: container or curtainsider
Enter the items in the consignment, each with its size, weight and whether it can carry load on top. The tool says whether it fits in the vehicle you pick, what the limiting factor is, and draws the plan. It loads with a real case so you can see how it works.
Items in the consignment
| Description | Shape | Length or diameter | Width | Height | Qty | Weight ea. | Bears load on top? | Position | Remove |
|---|
What it actually does
Pallet calculators assume every item is identical. A project consignment is not: there is a large piece that only travels one way up, crates that bear load, and pallets that do not. At that point the problem stops being arithmetic and becomes fitting.
The tool places items like this:
- Checks each item can get in. Separately: that its height clears the door (or the internal height, for side-loading vehicles) and that its shorter side fits the width.
- Places the tallest first, in rows spanning the full width. For each item it tries both orientations and keeps the one fitting more units per row, unless you marked it fixed.
- Stacks what can be stacked. An item that bears load takes others of its kind on top, up to the internal height. Note the distinction: each unit has to clear the door individually, but the finished stack can reach the roof.
- Lifts low items onto the ones that bear load. This is the step that saves consignments most often: what will not fit on the floor fits on top of something else.
- Adds up the floor length and compares it with the vehicle. And adds the weight against the payload.
The vehicles
| Vehicle | Internal L × W × H | Entry height | Payload | Loads from |
|---|---|---|---|---|
| 20 ft container | 5,898 × 2,352 × 2,393 | 2,280 mm | ≈ 28,180 kg | Rear door |
| 40 ft container | 12,032 × 2,352 × 2,395 | 2,292 mm | ≈ 28,750 kg | Rear door |
| 40 ft high cube | 12,032 × 2,350 × 2,700 | 2,597 mm | ≈ 28,600 kg | Rear door |
| 45 ft high cube | 13,556 × 2,352 × 2,698 | 2,597 mm | ≈ 27,600 kg | Rear door |
| Curtainsider | 13,620 × 2,450 × 2,700 | 2,700 mm | ≈ 24,000 kg | Side and roof |
| Mega trailer | 13,620 × 2,480 × 3,000 | 3,000 mm | ≈ 24,000 kg | Side and roof |
| Rigid truck | 7,200 × 2,450 × 2,600 | 2,600 mm | ≈ 12,000 kg | Side and rear |
Container figures come from carrier specification sheets. They vary by a few millimetres between manufacturers and ages, and with an item that is tight on height it is worth measuring the door of the actual container before loading. Curtainsider figures vary more still by bodybuilder, so there the assigned vehicle's own numbers govern entirely.
Goods do not enter a container through the roof: they enter through the door, and the door is lower than the interior. A 40 ft standard is 2,395 mm inside but only 2,292 at the door. A 2,200 mm item fits on paper and does not go in reality, because getting it in means lifting it on forks and that eats the 9 cm of clearance. This tool checks the two heights separately.
Curtainsided vehicles load from the side, and many open the roof too. For a tall or awkward piece, or anything that has to go in by crane, a curtainsider solves what a container cannot, even with less payload. The tool accounts for this: for side-loading vehicles it only checks the internal height.
A 1,600 mm crate is stackable, but two stacked are 3,200 and no maritime container has that internal height. What is useful is the opposite: that it bears load on top, so low items that would otherwise need floor space can go up there. The tool tests this on its own, and in the case loaded by default it is the only thing that makes the consignment fit.
The case loaded by default
It is a real consignment: a round piece on legs, 3,000 × 2,000 × 2,200 mm and 3,500 kg, which only travels one way up; four crates of 2,000 × 2,000 × 1,600 at 300 kg that do bear load on top; and three pallets of 1,200 × 800 × 600 at 500 kg that bear nothing.
Select the 40 ft standard and the first trap appears: the piece is 2,200 and the door 2,292. Ninety millimetres of clearance, which evaporate the moment you lift it on forks. Switch to high cube and the door becomes 2,597 — that works.
The second trap is the crates. They are stackable, but two are 3,200 mm and the high cube interior is 2,700: they cannot be stacked on each other in any maritime container that exists. What is useful is that they bear weight, and the pallets go up there: 1,600 of crate plus 600 of pallet is 2,200, with half a metre of air.
Without that last step the consignment does not fit. On the floor, the piece and the four crates take 11,000 mm of the 12,032; the three pallets would need 2,400 more and only 1,032 remain. Lifted on top, everything goes in with a metre to spare at the door.
Try the curtainsider too: it loads from the side, so door height leaves the problem entirely and the round piece goes in without argument. You trade payload for that, though with 6.2 tonnes it makes no difference here.
Where this calculator stops being accurate
- It places by rows, it does not solve optimal packing. Every row takes the full width. A skilled loader tucks small items into the side gaps this tool leaves empty, so with many small items the real result will beat this one. Fine as a minimum plan; not an optimisation.
- Only one item type on top of each row. It will not mix two different types over the same base, even where they would both fit.
- It checks nobody's strength. Whether an item "bears load on top" is your call. The tool does not know how much it bears, and the difference between carrying one 500 kg pallet and three is exactly where things break.
- No weight distribution or axle limits. A load can be legal on total weight and illegal per axle. That belongs to whoever plans the transport with the actual vehicle.
- No load securing. The leftover gap has to be blocked, and that can force a different arrangement from the one shown here.
- Point loads. A heavy piece on legs or wheels concentrates load per square centimetre. A container floor is built for the wide wheel of a forklift, not a leg. That is solved with dunnage or a cradle, and the tool does not account for it.
Questions people actually ask
Why are the door height and the internal height different?
Because the door frame of a container sits below the roof: there is a header beam and the hinges. On a 40 ft standard the difference is 103 mm and on a high cube about 100. It sounds trivial until you have an item that is tight, and then it is the whole difference between loading and not loading. A stack built inside can reach the internal height; what has to clear the door is each individual item.
When is a curtainsider better than a container?
When the goods are tall, awkward, or have to go in by crane, because a curtainsider opens at the side and often at the roof. Also when the movement is by road within Europe and there is no need to containerise. The container wins on sea freight, on payload and on security. If your problem is 'it will not go through the door', the answer is usually curtains.
What do I put for “bears load on top”?
Yes only if the packaging is designed for it: timber crates with a frame, caged pallets, cartons with a sufficient compression rating. When in doubt, no. It is the field that changes the answer most and the one that costs most if you guess, because the plan will say it fits and on the loading bay it will not.
What is the fixed position for?
For anything that can only travel one way up: pieces on legs, machinery that cannot be laid down, reels that stand upright. Mark it and the tool will not try to rotate it, even where rotating would fit better. Leave it unmarked and it tries both orientations and keeps the better one.
What working clearance should I use?
Between 50 and 100 mm when planning. A vehicle loaded to the millimetre cannot be worked, and there is always a chock, a strap or a pallet that is less square than the drawing. Zero gives you the theoretical maximum, which is useful for knowing how much real margin you have, not for handing to the loading crew.
Does what I type leave my computer?
No. The calculation runs entirely in your browser. The copy-link button puts your items inside the address itself, so you can pass the plan to your forwarder without it touching any server of ours.
Is something missing from this calculator? Tell us here