How to plan a cargo load
- Measure the loaded unit. Length, width and loaded height (for a pallet, include the deck, usually 144 to 150 mm), plus the gross weight of one unit.
- Pick the equipment by its inside size. Plan to the interior dimensions and the maximum payload, never the outside size. The container and trailer dimensions pages list both.
- Decide what can stack and what must stay upright. Fragile, liquid and top-heavy freight usually cannot carry weight, and marked cartons must not be laid on their side.
- Fill the floor first, then go up. The floor pattern sets the count. Turning some pallets 90° often fits one or two more than straight rows: a 20ft container takes 11 Euro pallets that way.
- Check weight before you trust the volume. Dense cargo reaches the payload long before the box looks full, and on the road the weight on each axle group is the real limit.
- Sequence the load. Heavy units low and spread along the length, the centre of gravity near the middle, and multi-drop freight loaded in reverse order of delivery.
The step-by-step version, with a worked example, is in how to make a container loading plan.
What a good load plan gets right
Free planner or full load planning software?
The planner above answers the single-size question honestly and instantly. When the cargo list gets longer, the full ContainerMath load planner does the rest:
| Capability | Free planner | Full planner |
|---|---|---|
| Cargo sizes per plan | One | Whole mixed manifests |
| Layout | Floor plan with stack heights | Interactive 3D, step by step |
| Payload check | ||
| Axle loads and centre of gravity | ||
| Multi-drop loading order | ||
| Import from Excel or a packing list | Yes, with AI import | |
| Loading plan PDF | ||
| Account | None | Free trial, no card |
Comparing tools? See the best container loading software compared on features and price, and the truck load planning guide for road freight.
Equipment the planner covers
46 containers, trucks, trailers and railcars, each with its interior dimensions and payload: 20ft, 40ft and 45ft containers including high cube, reefer, open top and flat rack; 53ft and 48ft dry vans, curtainsiders and reefer trailers; box trucks; Indian road trucks from the Tata Ace to the 32ft MXL; and rail boxcars. Quick answers for common pairs:
Cargo load planner FAQ
What is a cargo load planner?
A cargo load planner is a tool that works out how cargo fits into a container, truck, trailer or railcar. It takes the size, weight and quantity of your pallets or cartons and the inside dimensions and payload of the equipment, then returns how many units fit, how they are arranged on the floor and how high they stack, whether space or weight runs out first, and how many loads the shipment needs.
Is this cargo load planner free?
Yes. The planner on this page is free and needs no account: the calculation runs in your browser and you can share a plan by copying the page link. The full ContainerMath planner, which handles mixed cargo, axle loads and loading order in 3D, has a free trial with no credit card.
How many pallets fit in a 20ft and a 40ft container?
On the floor, a 20ft container takes 11 Euro pallets (1200 × 800 mm) or 9 standard pallets (1200 × 1000 mm), and a 40ft container takes 25 Euro or 22 standard pallets, with pallets turned to the best orientation. Double stacking doubles those counts only when the loaded pallets are low enough and strong enough to stack, and heavy pallets can hit the payload limit first.
Can it plan trucks and trailers as well as containers?
Yes. It covers 46 equipment types: ISO containers (10ft to 45ft, high cube, reefer, open top and flat rack), North American and European semi-trailers (a 53ft dry van takes 30 GMA pallets on the floor), box trucks, Indian road trucks and rail cars. For road loads, the full planner also checks the weight on each axle group, which is what decides whether a truck is legal.
Does the planner check weight as well as space?
Yes. Enter the gross weight of one unit and the planner compares the total against the equipment's maximum payload, then tells you whether space or weight is the binding limit. Dense cargo often reaches the payload long before the container looks full.
Can I plan mixed cargo with different box sizes?
This free planner handles one cargo size at a time. For a manifest with several sizes, stacking rules and delivery stops, the full ContainerMath planner packs every line together in 3D, checks axle loads and centre of gravity, and exports a loading plan PDF. You can import the cargo list from Excel or paste a packing list.
How accurate are the counts?
For pallet-sized units the floor count is the exact geometric maximum, mixing orientations where that fits more. For small cartons the planner uses the best block pattern, which can be a unit or two below the theoretical maximum. Both assume units touching, so allow some clearance for forklifts, and check the door opening for the last row.
What is the difference between a load planner and a CBM calculator?
A CBM calculator adds up volume: it tells you how many cubic metres your cargo is and roughly which container size it needs. A load planner places the actual units, so it catches what volume hides: cartons that leave a gap at the wall, pallets that cannot stack, and loads that reach the weight limit first.