Container Loading Calculator

Volume or weight, only one is binding.

Volume or weight, only one is binding. A container fills on volume or on weight, and only one of them is binding.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these

Currency

Container

Volume per carton

m³

Weight per carton

Container weight limit

Space lost to stowage

Units per carton

Freight cost for the container

Units per container

19,644

$0.163 of freight each

Cartons by volume1,637

Cartons by weight2,888

Cartons loaded1,637

Binding constraintvolume

Volume is binding, so the container fills before it gets heavy. Reducing carton size or improving nesting adds units directly; reducing weight adds nothing.

How the Container Loading Calculator works

A container fills on volume or on weight, and only one of them is binding. Reducing carton size when weight is the constraint adds nothing; reducing weight when volume is the constraint adds nothing either. Knowing which is which decides the whole packaging brief.

Also known as: how many cartons fit in a container · container fill calculator · 40ft container capacity · container stuffing calculator · 3D container loading calculator

The two limits, and which one binds

A container has a volume limit and a weight limit, and almost every shipment hits one long before the other. Light bulky goods cube out: the box is full and the weight is nowhere near the limit. Dense goods weigh out: the container is at maximum payload with space left.

Knowing which applies changes what you optimise. Cubing out means packaging efficiency and stacking height are what matter. Weighing out means the volume is free and the question is entirely about payload distribution.

Approximate internal capacities are worth having to hand. A 20 foot container offers roughly 33 cubic metres and a payload around 28 tonnes. A 40 foot gives about 67 cubic metres with a similar payload, which is why a 40 foot is barely more expensive to ship than a 20 foot for light cargo and no better at all for dense cargo.

The gap between theoretical and achievable fill

Divide container volume by carton volume and you get a number nobody achieves. Real loading runs 80% to 90% of theoretical for palletised freight and can reach 95% for hand-stacked uniform cartons.

The losses are structural. Pallets themselves occupy 150mm of height each and do not tile perfectly into the container width. Cartons rarely divide evenly into the internal dimensions. Space has to be left for dunnage and bracing so the load does not shift. The container floor is not perfectly flat and the walls are corrugated.

Floor loading, meaning hand-stacking without pallets, gains perhaps 10% to 15% of capacity and costs considerably more in labour at both ends. It is standard practice from Asia where loading labour is cheap and rarely worth it in reverse.

Pallets in a container, which is an awkward fit

A 20 foot container takes 10 or 11 UK pallets on the floor depending on orientation. A 40 foot takes 20 to 21. Euro pallets fit slightly differently, with 11 in a 20 foot and 23 or 24 in a 40 foot, because the 800mm dimension tiles better against the 2352mm internal width.

Double stacking doubles those numbers where the goods and the height allow. A standard container has 2393mm of internal height, so two pallets of 1100mm loaded height plus the pallets themselves fits comfortably. Whether the goods take the weight of another pallet on top is the constraint that usually decides it.

High cube containers add roughly 300mm of internal height, which is frequently the difference between double stacking and not. The freight premium for a high cube is small and the capacity gain can be 30% for the right cargo, which makes it one of the better-value upgrades in freight.

Weight distribution, and why it is not optional

Load has to be distributed evenly along the container floor. Concentrating weight at one end shifts the centre of gravity, which affects handling at the port, on the chassis and on the vessel, and containers loaded badly are refused or surcharged.

Under SOLAS rules the verified gross mass of a packed container must be declared before loading, and the declaration has to be accurate. Getting it wrong is a compliance issue with real consequences rather than an estimate anyone tolerates.

Road weight limits at the destination are the constraint that catches importers. A container legally loaded at origin may exceed the axle weight limits for road transport at destination, at which point it has to be partially unloaded at the port at considerable cost. Checking the destination road limit before loading is the fix and it is regularly skipped.

LCL, FCL and the crossover between them

Less than container load is priced per cubic metre and suits small shipments. Full container load is priced per container and becomes cheaper per unit above a threshold, typically somewhere around 13 to 15 cubic metres depending on route and rates.

The crossover is worth calculating rather than assuming, because LCL carries charges that FCL does not: consolidation, deconsolidation, and per-shipment documentation that does not scale down. A 12 cubic metre LCL shipment can cost close to a full 20 foot container once those are counted.

LCL also takes longer and carries more damage risk, because the goods are handled at consolidation and deconsolidation points and share space with other people's cargo. For fragile or high-value goods the effective cost of LCL is higher than the rate suggests, which pulls the crossover point down further than the pure freight arithmetic implies.

Where to go next

The Container Loading question rarely arrives on its own. These are the ones that usually come with it:

Pallet Count Calculator — Carton dimensions decide the pallet fill.
Container Import Cost Calculator — Cost per unit across a full container.
Freight Cost Calculator — Sea, air and road freight per unit.
Etsy Fee Calculator — Every Etsy fee on one sale, itemised.

Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price, check the platform's current fee schedule before you price a product against it. This is not tax or business advice.

Frequently asked questions

How much fits in a container?

A 20-foot holds roughly 33 cubic metres of usable volume and a 40-foot around 67, before stowage losses. Weight limits are typically 21 to 26 tonnes depending on the container and route.

What are stowage losses?

Space that cannot be used because of how cartons pack: gaps at the door, uneven layers, dunnage. Ten to fifteen percent is a normal allowance.

Which constraint binds more often?

Volume, for most consumer goods. Dense products such as liquids, tools or ceramics hit the weight limit first, and for those a smaller carton ships air.