Container Loading Calculator

Calculate how many cartons fit in a shipping container, using the smaller of the volume-based and weight-based capacity limits.

Quick Facts

Method
Loadable qty = min(volume-limited, weight-limited)
The smaller of what fits by cubic space and what fits under the max payload sets the real count.
Packing efficiency
Typically 70-90% of rated volume
Pallet gaps, case shape, and aisle space keep real loads below the container's rated cubic capacity.

Your Results

Calculated
Total loadable cartons
-
Smaller of the volume and weight limits
Volume utilization
-
Share of container volume filled
Weight utilization
-
Share of max payload used
Limiting factor
-
Constraint that caps the load

Ready

Enter carton dimensions, weight, and container type, then press Calculate.

About the Container Loading Calculator

This tool estimates how many identical cartons or cases fit inside a standard shipping container, using the two limits that govern every real load: the space available and the weight allowed. It reports whichever limit is more restrictive, since a container can never carry more than either boundary permits.

The formulas

For a container with rated internal volume V and maximum payload P, loading a carton of volume v and weight w:

  • Volume-limited quantity: floor((V × packing efficiency) ÷ v) — how many cartons fit in the usable cubic space.
  • Weight-limited quantity: floor(P ÷ w) — how many cartons the container can legally carry before hitting its maximum payload.
  • Loadable quantity: the smaller of the two — min(volume-limited, weight-limited) — because both constraints must be satisfied at once.

Packing efficiency (default 85%) discounts the container's rated volume to account for real-world losses: pallet footprints that don't tile perfectly, case shapes that leave gaps, door-swing clearance, and bracing or dunnage. Loose-stacked rectangular cartons typically achieve roughly 70-90% of rated volume; adjust the input down for irregular cargo or up for tightly modular, palletized loads.

Reading the result

When the volume-limited number is lower, the load is volume-limited — the container runs out of room before it gets heavy, which is typical for bulky, lightweight goods like foam, textiles, or empty packaging. When the weight-limited number is lower, the load is weight-limited — the payload cap is reached with cubic space to spare, typical for dense cargo like liquids, machinery, or metal stock. Volume utilization and weight utilization show what share of each limit the final load actually uses; a large gap between the two tells you which lever (a bigger/lighter carton, or a denser one) would improve the fill.

Standard container reference values

Internal volumes and maximum payloads used by this calculator are typical published figures for ISO dry containers: a 20ft standard container holds about 33.2 m³ with a maximum payload near 28,180 kg; a 40ft standard container holds about 67.7 m³ with a maximum payload near 28,780 kg; a 40ft high cube holds about 76.4 m³ with a maximum payload near 28,580 kg. These vary slightly by manufacturer and container age — check the data plate on the actual unit for a weight-critical shipment.

Frequently Asked Questions

How is the loadable quantity calculated?
The calculator finds two limits and takes the smaller one. The volume limit divides the container's usable cubic volume (its rated volume times your packing efficiency percentage) by one carton's volume. The weight limit divides the container's maximum payload by one carton's weight. Whichever limit is lower is the real loadable quantity, because a load can never exceed either the available space or the legal weight limit.
Why isn't packing efficiency 100%?
A container's rated cubic volume assumes every corner is filled perfectly, which real cargo never achieves. Pallets, irregular case shapes, door swing clearance, and load bracing leave gaps. Loose cartons stacked by hand typically achieve about 70-90% of rated volume, palletized loads often land lower, and the default of 85% is a reasonable planning estimate that should be adjusted for your actual packing method.
What does volume-limited or weight-limited mean?
A load is volume-limited when the container runs out of usable space before it reaches its weight limit — typical for bulky, lightweight cargo. It is weight-limited when the maximum payload is reached while cubic space is still available — typical for dense, heavy cargo like liquids or metal parts. Knowing which constraint binds tells you whether a bigger container or a lighter/denser carton would help.
Are the container volume and payload figures exact?
The internal volume and maximum payload used here are typical published figures for ISO dry containers and vary slightly by manufacturer, container age, and shipping line. For a booking or a weight-critical shipment, confirm the exact tare weight and internal dimensions on the specific container's data plate.

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