Container load calculator
Calculate how many cartons or pallets fit in a 20ft, 40ft, 40ft high cube or 45ft container, loose or palletised, and whether volume or payload runs out first.
660 cartons per 40ft high cube (40' HC)
45ft high cube (45' HC) is 471 cartons higher than 20ft standard (20' GP) — a 65% difference.
| Step | Working | Result |
|---|---|---|
| Cartons on the container floor | 30 × 3 crosswise + 20 rotated in the gap | 110 |
| Stack layers | floor(269 ÷ 40) | 6 |
| Cartons per container | 660 | |
| Containers needed | ceil(800 ÷ 660) | 2 |
Step 3 of 4 — I am planning freight
How does this load pack, and what class does it move at?
Two limits, and only one of them usually binds
A container has a volume limit and a payload limit, and for almost everything a consumer-goods importer ships, the volume runs out first. The box fills, the doors close, and the weight is nowhere near the plate. That flips above roughly 400 kg per cubic metre — tiles, stone, liquids, batteries, machinery, anything dense — where the payload limit binds and the container leaves half empty by eye. Knowing which of the two is your binding constraint tells you what to optimise: packaging for the first, order size for the second.
The nominal internal volumes are about 33 CBM for a 20 foot standard, 67 for a 40 foot standard and 76 for a 40 foot high cube. Nobody achieves them. Cartons do not tile perfectly, pallets waste both floor and height, and the last metre by the doors has to stay workable. Planning to 85 to 90% of nominal is realistic; planning to 100% produces a shipment that does not fit and a decision to make on the dock.
The destination's weight limit, not the container's
The number that catches importers is not the container's payload rating but the road weight limit at the delivery end. A container legally loaded at origin can be over the axle limit for the truck that has to take it the last fifty miles, and the remedy — stripping and re-delivering part of the load — costs more than the freight saved by filling it. If you are shipping dense goods, confirm the destination road limit before deciding how much to put in the box.
Questions people ask about this
Answers written from the published rules, not from other people's summaries of them. Every figure quoted below is listed with its source at the foot of this page.
Every formula on this siteHow many CBM fit in a 20ft container?
A 20ft standard container has about 33 cubic metres of internal volume, but you will rarely load more than 28 to 30 because cartons do not tile perfectly and you need to be able to close the doors. A 40ft standard is about 67 CBM and a 40ft high cube about 76.
What limits a container load, volume or weight?
For most consumer goods, volume. The box fills before the payload limit is reached. Dense cargo — tiles, liquids, machinery, anything above roughly 400 kg per cubic metre — hits the weight limit first, and road weight limits at the destination can be lower than the container's own.
Should I ship loose or palletised?
Loose loading fits more, often 10 to 15% more, because pallets waste both floor space and height. Palletised is faster to load and unload, less prone to damage, and sometimes required by the receiving warehouse. If your destination charges by the hour to unload, palletised usually wins on total cost.
Is a 40ft high cube worth the extra cost over a 40ft standard?
It depends entirely on whether you can use the height. A high cube adds about a foot of internal height — roughly 9 CBM, or 13% more volume — for a modest premium, so for light, bulky cargo it is almost always the better value. But the extra height is only usable if your pallet configuration can take another tier or a taller one. If your stack height is fixed by carton crush strength or by a warehouse rule, you are paying for headroom you cannot fill.
How much does palletising cost me in container space?
Typically 10 to 15% of the load. Pallets waste floor space where the footprints do not tile the container width, and height in the base of every stack. Against that, palletised freight loads and unloads in a fraction of the time, damages less, and is often mandatory at the receiving warehouse. If your destination charges by the hour to devan a container, palletised usually wins on total landed cost even though it fits less.
What is the difference between a 45ft container and a 40ft high cube?
Length, and acceptance. A 45 foot high cube adds about five feet over a 40 foot high cube for roughly 10% more volume. The catch is that it is not universally accepted — some ports, some road networks and some chassis cannot take it, and availability on any given lane is much thinner than for the 40 foot sizes. Confirm the equipment is actually available on your route before building a loading plan around it.
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Where these numbers come from
Rates and rules change, and a calculator running on stale data is worse than no calculator. Every figure below carries the date we last checked it and a confidence level, so you can judge how much weight to put on it.
| Source | Publisher | Effective | Confidence |
|---|---|---|---|
| ISO 668 — freight container internal and door dimensions Internal length, width, height, door opening, cubic capacity, tare and maximum payload for 20ft, 40ft, 40ft high cube and 45ft high cube boxes. The citation points at our own worked figures rather than at ISO because ISO 668 is a paid standard that cannot be linked to a page a reader can open, and iso.org refuses automated requests. The more useful caveat is that real boxes vary: internal dimensions differ by manufacturer and by age, so these are the nominal figures and your actual container may be a few centimetres off. The door opening is the constraint that catches people out — a 40ft high cube door is about 258 cm against an internal height of 269 cm, so a pallet that fits the box may not fit through the door. | ISO 668 (series 1 freight containers) | Not specifiedChecked 2026-08-25 | Corroborated |
Page updated . Spotted something out of date? Tell us — corrections are published with the date they were made.
More on the working: every formula on this site, the full source register, what the terms mean, and how we decide what to publish. What an estimate here can and cannot support is set out in the accuracy notes.