Container Load Calculator
Work out how many cartons fit in a 20GP, 40GP, 40HQ or reefer container, and how many containers you need for the shipment.
Quick answer
Enter carton dimensions, unit weight and total quantity. The calculator tests all six box orientations against each container's internal dimensions, keeps the arrangement that fits the most cartons, then applies the payload limit. It returns units per container, containers needed, plus volume and payload utilisation.
Container Load Calculator
Loading plan
- Arrangement
- 30 along length × 7 across width × 7 layers high
- Volume used — 55%
- Payload used — 45%
- Total cargo volume
- 36.00 m³
- Total cargo weight
- 12000 kg
Top view of one layer
All container types compared
| Container | Internal (cm) | Capacity | Max payload | Fits | Needed |
|---|---|---|---|---|---|
| 20GP | 590×235×239 | 33.2 m³ | 28.0 t | 686 | 2 |
| 40GP | 1203×235×239 | 67.7 m³ | 26.5 t | 1470 | 1 |
| 40HQ | 1203×235×270 | 76.4 m³ | 26.5 t | 1680 | 1 |
| 45HQ | 1356×235×270 | 86.1 m³ | 27.6 t | 1890 | 1 |
| 20RF | 545×229×227 | 28.3 m³ | 27.4 t | 637 | 2 |
| 40RF | 1158×229×250 | 66.3 m³ | 27.7 t | 1596 | 1 |
| 20OT | 590×233×233 | 32.1 m³ | 28.0 t | 686 | 2 |
| 40OT★ | 1200×233×233 | 65.2 m³ | 26.6 t | 1470 | 1 |
Estimates only. Container figures are typical ISO specifications and vary by carrier. Always confirm the final loading plan with your forwarder.
How the calculation works
- 1All six carton orientations are tested against the container's internal length, width and height.
- 2The arrangement with the highest count wins, after subtracting the gap you set between cartons.
- 3The payload limit is applied: units per container cannot exceed max payload divided by unit weight.
- 4Containers needed is total quantity divided by units per container, rounded up.
Container specifications used
Typical ISO specifications. Actual figures vary by carrier, container owner and build year.
Internal (cm) · Capacity · Max payload · Door opening
Methodology and limits
The result is a theoretical maximum from a rectangular packing model. It assumes cartons are rigid, stackable and can be rotated, and that the load is evenly distributed. Real loading is affected by pallets, dunnage, carton deformation, stacking strength, axle weight rules and stowage order. Treat the output as a planning estimate and confirm the final plan with your forwarder or loading supervisor.
Frequently asked questions
What is the difference between a 40GP and a 40HQ?
Both are the same length and width. A 40HQ is about 30 cm taller inside (269 cm versus 239 cm), which adds roughly 9 m³ of capacity. The payload limit is nearly identical, so the high cube only helps when you run out of space before you run out of weight.
Why is your number different from my forwarder's?
Three common reasons. First, container internal dimensions vary slightly by carrier and build year. Second, this model assumes cartons are rigid and fully stackable, while real loading needs pallets, dunnage and tolerances. Third, weight distribution and road axle limits can cap the load below the container's maximum payload.
Should I set a gap between cartons?
Yes, for planning. Set 2 to 5 cm if cartons are packed by hand or may bulge. Set 0 only for rigid, uniform cartons on a tightly controlled load.
Does this handle pallets?
Not directly in this version. To approximate a palletised load, enter the pallet footprint and height including the pallet base as one unit, and set the quantity to your pallet count.
Are these container specifications exact?
No. They are widely used typical figures for planning. Dimensions and payload limits differ by container owner, manufacturer and build year, and shipping lines publish their own limits. Confirm with your carrier before booking.
What if my cartons cannot be stacked?
Enter the carton height as the full stack height you are willing to allow, or reduce the quantity per layer manually. This version assumes every carton carries the load above it.
Related tools
Provided for general guidance. It does not independently verify any supplier and is not legal, financial or professional audit advice.