Container Capacity Calculator

Calculate shipping container capacity in CBM, weight, and carton count. Covers 20ft, 40ft, 40ft High Cube, and Reefer containers.

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How to Calculate Container Capacity

Container capacity comes down to three numbers: volume (CBM), weight, and how efficiently your cartons pack — whichever one runs out first sets your real limit.

Capacity = Container Volume ÷ Carton Volume × Packing Efficiency
Container TypeVolume (CBM)Max Payload
20ft Standard~32.9 m³28,000 kg
20ft Reefer~28.3 m³27,700 kg
40ft Standard~67.6 m³26,500 kg
40ft High Cube~76.3 m³26,460 kg
40ft Reefer High Cube~66.0 m³27,700 kg
⚖️ Volume vs. Weight — Which One Limits You?

Light, bulky cargo (garments, furniture, packaging) usually runs out of volume first — the container looks full long before it hits its weight limit. Dense, heavy cargo (metal parts, canned goods, tiles) usually runs out of weight first — you'll have empty space left but can't legally load any more. ContainerLoad calculates both simultaneously and tells you which one is actually capping your shipment, so you're never guessing.

📦 Why "Volume ÷ Carton Volume" Alone Is Wrong

Dividing total volume by carton volume gives a theoretical maximum that real-world loading never hits — cartons don't tessellate perfectly against a container's walls, pallets add wasted space, and stacking height has practical limits well below the container's full height. Real packing efficiency for floor-loaded cartons is typically 75–92% depending on carton dimensions relative to the container; for palletized loads it's usually lower once you account for pallet footprint and stacking gaps. ContainerLoad simulates the actual layer-by-layer, pallet-by-pallet placement rather than using a rough divide, so the count you get matches what will really fit.

Frequently Asked Questions

How do I calculate container capacity?
Container capacity = (container volume ÷ carton volume) × packing efficiency. In practice, use a calculator that simulates the real layer-by-layer or pallet-by-pallet placement — enter your carton dimensions and weight, and ContainerLoad calculates the exact count automatically, accounting for both volume and weight limits.
What is CBM in shipping?
CBM (Cubic Metre) is the standard unit for measuring shipping container volume. 1 CBM = 1m × 1m × 1m. A 20ft container is approximately 33 CBM, a 40ft container approximately 67 CBM, and a 40ft High Cube approximately 76 CBM.
How do I know if my shipment is volume-limited or weight-limited?
Compare your total shipment weight against the container's max payload, and your total shipment volume against the container's CBM. Whichever percentage is higher is your binding constraint. Dense cargo is usually weight-limited; light bulky cargo is usually volume-limited. ContainerLoad shows both percentages side by side for every calculation.
What packing efficiency should I assume?
Floor-loaded cartons typically achieve 75–92% packing efficiency depending on how well your carton dimensions divide into the container's internal dimensions. Palletized loads are usually somewhat lower due to pallet footprint and stacking gaps. Rather than assuming a rough percentage, ContainerLoad calculates your actual efficiency based on your specific carton size.

Get Your Exact Capacity — Not an Estimate

Enter your carton dimensions and weight, and see exactly how many fit — with the real limiting factor called out.

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