Container Loading Calculator
Estimate how many identical boxes or units fit inside a shipping container, based on item size, container volume, and a realistic packing efficiency.
Reviewed by the CalcCafe editorial team · Last updated 1 July 2026 · How we test our tools
Example
A box measuring 40 × 30 × 30 cm has a volume of 40 × 30 × 30 ÷ 1,000,000 = 0.036 m³. In a 20ft container (33.2 m³) at 85% packing efficiency, the usable space is 33.2 × 0.85 = 28.22 m³, so you can fit floor(28.22 ÷ 0.036) ≈ 783 units.
How it works
Item volume (m³) = length × width × height ÷ 1,000,000 (converting cm³ to m³). Usable volume = container volume × packing efficiency%. Units that fit = floor(usable volume ÷ item volume), rounded down because you cannot ship a partial box.
Good to know
Working out how many cartons fit in a shipping container is one of those questions that looks like simple division but trips people up because a container is never packed to 100% of its rated volume. This tool takes an item's three dimensions in centimetres, the container's cubic-metre capacity, and a packing efficiency figure, then returns how many identical units realistically fit. It is aimed at importers, e-commerce sellers, and anyone estimating freight before booking a slot.
The packing efficiency field is where the estimate earns its keep. Boxes leave gaps: they rarely tile perfectly, pallets eat floor space, and you lose height near the doors and roof. A cube-utilisation of 80–90% is a common planning range for uniform cartons stacked by hand, while palletised or awkwardly sized goods can drop well below that. Lower the percentage if your items do not stack cleanly or must ship on pallets.
The two reference volumes to know are roughly 33.2 m³ for a standard 20ft container and 67.7 m³ for a 40ft, though exact interior capacity varies by manufacturer and whether it is a high-cube unit. Swap the container volume field to match the equipment your forwarder quotes. Because the result uses a floor, it counts only whole boxes that fit inside the usable space.
Treat the output as a volumetric ceiling, not a loading plan. It ignores weight limits (heavy goods often hit the container's payload cap long before they fill it), item orientation and non-stackable constraints, dunnage, and the door aperture. For a real shipment, confirm gross weight against the container's rating and let your freight forwarder verify the final load.
Frequently asked questions
How many boxes fit in a 20ft container?
It depends entirely on box size. A 20ft container holds about 33.2 m³, and at 85% packing efficiency you get roughly 28 m³ of usable space — divide that by your item's cubic-metre volume for a whole-box estimate. This tool does the math for you.
What packing efficiency should I use?
For uniform cartons stacked by hand, 80–90% is a reasonable planning range; palletised or irregular goods often pack at 60–75%. Lower the figure when items do not stack cleanly or must travel on pallets.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser. Your inputs never leave your device, and it works offline once loaded.
Is this calculator free?
Yes, completely free with no sign-up and no limits.
People also ask
How do you calculate how many items fit in a container?
Convert the item's dimensions to cubic metres (length × width × height in cm ÷ 1,000,000), multiply the container volume by your packing efficiency to get usable space, then divide usable space by item volume and round down to whole units.
What is the volume of a 40ft shipping container?
A standard 40ft container has an internal capacity of about 67.7 m³, while a 40ft high-cube offers roughly 76 m³. A 20ft container holds around 33.2 m³. Exact figures vary slightly by manufacturer.
Why can't I fill a container to 100%?
Boxes rarely tile perfectly, you lose height near the roof and doors, pallets consume floor space, and awkward shapes leave voids. Real cube utilisation is usually 80–90% for neat cartons and lower for irregular loads.
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Sources & references
These tools follow our methodology and provide educational estimates only — verify important figures with a qualified professional.