Container Load Calculator
Work out how much cargo fits in a shipping container or truck. Enter your boxes, pallets, sacks or drums, pick a container, and get a 3D load plan with volume and weight utilization. Runs entirely in your browser — free, no signup, nothing uploaded.
Groups keep separate consignments apart and can be pinned to specific containers. Use the ⚙ on any row for stacking limits, load-bearing capacity and orientation locks.
How the container load calculator works
Container stuffing is a three-dimensional bin packing problem: fit a set of boxes into the fewest containers without overlaps, without exceeding the payload, and without stacking anything on cargo that cannot take the weight. The problem is NP-hard, so no tool — this one included — guarantees a mathematically optimal load. What good tools do is apply a heuristic that gets close, fast.
This calculator uses an Extreme Point heuristic with First Fit Decreasing ordering:
- Cargo is expanded into individual units and sorted largest volume first — big awkward items get the best positions while the container is still empty.
- The packer keeps a list of extreme points: candidate corners where a box could go, starting with the container origin.
- Each unit is tested against every extreme point in every permitted orientation. Placements that overlap, poke through a wall, float unsupported, or crush a non-stackable item are rejected.
- Of the valid placements, the lowest wins — then the deepest, then the leftmost. This keeps the centre of gravity down and fills from the nose of the container.
- Placing a box spawns new extreme points on its right, far, and top faces. When nothing else fits, the next container opens.
A box is only placed if at least 75% of its base is supported by the floor or by the top faces of boxes beneath it, which is why results look like loads a person could actually build rather than a floating puzzle.
Standard container internal dimensions
Container names refer to exterior length — a "40 foot" box is 12,192 mm outside but only about 12,029 mm inside once walls and doors are accounted for. Always plan against internal dimensions:
| Container | Length (mm) | Width (mm) | Height (mm) | Volume (m³) | Payload (kg) |
|---|---|---|---|---|---|
| 20' Standard | 5,898 | 2,352 | 2,393 | 33.2 | 28,200 |
| 40' Standard | 12,029 | 2,350 | 2,392 | 67.6 | 26,700 |
| 40' High Cube | 12,029 | 2,350 | 2,697 | 76.2 | 26,460 |
| 45' High Cube | 13,556 | 2,352 | 2,698 | 86.0 | 27,600 |
| 20' Reefer | 5,449 | 2,290 | 2,244 | 28.0 | 27,700 |
| 40' Reefer High Cube | 11,577 | 2,290 | 2,249 | 59.6 | 27,700 |
| 20' Open Top | 5,898 | 2,352 | 2,340 | 32.5 | 28,100 |
| 40' Open Top | 12,029 | 2,350 | 2,340 | 66.1 | 26,600 |
| 20' Flat Rack | 5,698 | 2,230 | 2,233 | 28.4 | 31,000 |
| 40' Flat Rack | 11,832 | 2,228 | 1,955 | 51.5 | 39,500 |
Figures are typical for ISO dry containers. Individual units vary by manufacturer and age — confirm against the CSC plate on the door for tight loads.
How many pallets fit in a container?
This is the single most common container question, and the answer depends on pallet footprint and whether you can double-stack:
| Pallet | 20' single layer | 40' single layer | 40' double-stacked |
|---|---|---|---|
| EUR / EPAL 1 (1200 × 800 mm) | 11 | 23-25 | 46-50 |
| US GMA (48 × 40 in) | 10 | 20-21 | 40-42 |
| EUR 2 (1200 × 1000 mm) | 9-10 | 20-21 | 40-42 |
Double-stacking only works if the loaded pallet height is under half the container interior — roughly 1,196 mm for a 40' standard, or 1,348 mm for a High Cube — and the lower pallet can carry the upper one. Use the calculator above with your real pallet dimensions rather than trusting a rule of thumb.
Standard pallet sizes
| Pallet type | Footprint (mm) | Typical max load |
|---|---|---|
| EUR / EPAL 1 (1200 × 800 mm) | 1200 × 800 | 1,500 kg |
| EUR 2 (1200 × 1000 mm) | 1200 × 1000 | 1,500 kg |
| US GMA (48 × 40 in) | 1219 × 1016 | 1,134 kg |
| EUR 3 (1200 × 1200 mm) | 1200 × 1200 | 1,500 kg |
| Asia (1100 × 1100 mm) | 1100 × 1100 | 1,000 kg |
| Half / EUR 6 (800 × 600 mm) | 800 × 600 | 500 kg |
Why utilization never reaches 100%
A container that reports 85% volume utilization is a good load. Boxes rarely tessellate perfectly: a 600 mm box across a 2,350 mm width leaves 150 mm of dead space in every row, and that gap repeats down the whole container. Stacking limits, orientation constraints, and mixed cargo sizes add more.
Watch both bars in the result panel. If weight hits 100% while volume sits at 40%, you have dense freight and should consider splitting across more containers to stay under the payload. If volume fills while weight is barely used, you are shipping air — the classic case for a High Cube, or for re-examining packaging.
Container load calculator FAQ
How many pallets fit in a 40ft container?
A 40' standard container has about 12,029 x 2,350 mm of usable floor, which holds 20-21 EUR pallets (1200 x 800 mm) or 20 US GMA pallets (48 x 40 in) in a single layer. If your cargo is short enough to double-stack within the 2,392 mm interior height, you can carry up to 40-42 pallets. A 40' High Cube adds ~300 mm of height, which rarely adds a pallet row but does allow taller loads per pallet.
How many pallets fit in a 20ft container?
A 20' standard container fits 10-11 EUR pallets (1200 x 800 mm) or 9-10 US GMA pallets (48 x 40 in) in one layer, and double that if the cargo can be stacked within the 2,393 mm interior height.
What are the internal dimensions of a 40ft container?
A 40' standard container measures approximately 12,029 mm long x 2,350 mm wide x 2,392 mm high inside, giving about 67.6 m3 of capacity with a maximum payload near 26,700 kg. Note that the nominal '40 foot' refers to the exterior length (12,192 mm); the usable interior is shorter because of the walls and doors.
How is container utilization calculated?
Volume utilization is the total volume of loaded cargo divided by the container interior volume. Weight utilization is total cargo weight divided by the maximum payload. Real loads rarely exceed 85-90% volume utilization because boxes cannot tessellate perfectly and stacking rules leave gaps.
Is this container load calculator free?
Yes. The calculator runs entirely in your browser, requires no signup, and has no usage limits. Nothing you enter is uploaded to a server.
What algorithm does the load calculator use?
It uses an Extreme Point heuristic with First Fit Decreasing ordering. Cargo is sorted largest-first, then each unit is tested against a set of candidate corner positions in every allowed orientation, choosing the lowest and deepest valid placement. 3D bin packing is NP-hard, so all container stuffing tools (including this one) use heuristics rather than guaranteed-optimal solutions.
Automating this in your own system?
Once you know what fits, the next questions are where it ships from and who carries it. FreightAPIs exposes seaport data for 210 countries and terminal locations for 11 LTL carriers as JSON — free tier included, no card required.