On published specifications a 20-ft standard container has about 33 m³ of interior space, a 40-ft standard about 67 m³ and a 40-ft high cube about 76 m³, each with a max payload near 28,000 kg. Usable space is always lower than the interior volume, and heavy cargo reaches the weight limit before it fills the box.
The container loading calculator checks a shipment against both limits a container has: space and weight. Enter pallets or cartons, and it shows the total cargo volume and weight, how much of the container’s volume and payload that uses, the approximate space left, and a simple grid estimate of how many units could fit. It is built for a first check before you book, not to replace a load plan.
How to Use the Container Loading Calculator
- Pick a 20-ft standard, 40-ft standard or 40-ft high cube container. Open “Container specs” to edit the interior size or payload for your actual unit.
- Choose pallets or cartons and enter the size of one unit, the quantity and the weight per unit.
- Tick stacking (pallets) or side-laying (cartons) only if the freight allows it.
- Read the volume and payload gauges, then the notes. Anything tight or over deserves a proper load plan.
How RapidShips Calculates This
- Formula
- cargo volume = L x W x H x quantityvolume used = cargo volume ÷ interior volumepayload used = cargo weight ÷ max payloadremaining volume = interior volume − cargo volume
- Grid estimate
- Units are placed in one plain grid (rows x columns x layers), all in the same orientation. Pallets may turn on the floor; cartons may also lie on their sides if you allow it. The orientation that places the most units wins. Pallets stack only when you tick it; cartons stack to the ceiling.
- Units and data
- Everything is converted to meters and kilograms with exact factors. Default interiors and payloads are Maersk’s published steel dry container figures and can be edited.
- What it ignores
- Mixed orientations, pallet overhang, dunnage and bracing, door clearance while loading, crush strength, center of gravity, axle weights and the weight limits of the truck that will pull the container.
Typical Container Specifications
| Container | Interior L x W x H | Door W x H | Volume | Max payload | Tare |
|---|---|---|---|---|---|
| 20-ft standard | 5,896 x 2,350 x 2,393 mm | 2,350 x 2,274 mm | 33 m³ | 28,200 kg (62,170 lb) | 2,280 kg |
| 40-ft standard | 12,032 x 2,350 x 2,393 mm | 2,340 x 2,274 mm | 67 m³ | 28,800 kg (63,493 lb) | 3,700 kg |
| 40-ft high cube | 12,032 x 2,350 x 2,697 mm | 2,340 x 2,577 mm | 76 m³ | 28,620 kg (63,100 lb) | 3,880 kg |
Source: Maersk dry container specifications.[1] Other lines and builders publish slightly different numbers, so the calculator lets you edit them.
How Many Pallets Fit in a Container?
Using the interiors above, 18 standard 48 x 40 in. pallets fit on the floor of a 40-ft standard or high cube in one tier, and 8 fit in a 20-ft. Stacking doubles that only when two loaded heights fit under the roof with clearance and the lower pallets can carry the upper ones. The pallet calculator covers footprint and floor counts for other pallet sizes and 53-ft trailers.
Why Volume Utilization Does Not Prove It Fits
- Orientation: boxes rarely divide the interior evenly, and “this side up” freight cannot be turned to fill gaps.
- Stacking: cartons and pallets can only be stacked as high as the bottom layer can carry.
- Packaging: pallets, overhang, bulging cartons and dunnage all take space the math does not see.
- Weight distribution: weight has to be spread along the floor; a legal gross weight can still overload one end or axle group.
- Container limits: max payload, door openings and floor strength differ by unit.
- Restrictions: U.S. road limits can be lower than container payload. Federal rules generally cap a truck at 80,000 lb gross on the Interstate System.[2] See container weight rules and cargo securement for palletized freight.
Worked Examples
Pallets in a 40-ft high cube. Twenty 48 x 40 x 50 in. pallets at 1,100 lb each are 31.46 m³ and 9,979 kg: about 41% of the volume and 35% of the payload. Only 18 fit on the floor in one tier, so the calculator flags it as tight. If the pallets can be stacked, two 50 in. tiers fit under the 106.2 in. roof and the grid holds 36.
Cartons in a 40-ft standard. Six hundred 60 x 40 x 40 cm cartons at 18 kg are 57.6 m³ and 10,800 kg, about 85% of the volume. The volume fits on paper, yet a simple grid places only 500: 20 along x 5 across x 5 high, because 2,350 mm of width takes five 40 cm cartons with 35 cm left over. That gap is the difference between volume and fit.
Frequently Asked Questions
How many pallets fit in a 40-ft container?
What is the difference between a 40-ft standard and a 40-ft high cube?
What is container volume utilization?
Can I load a container up to its max payload?
Can this calculator plan my load in 3D?
Related Freight Tools
Related Guides and Services
Sources
- Maersk, “Our fleet: equipment specifications, dry containers (PDF),” accessed September 2026.
- Legal Information Institute, Cornell Law School, “23 CFR § 658.17: Weight,” accessed September 2026.
This page is general operational information, not a load plan or engineering advice. Confirm container specs, weights and legal limits with your carrier and trucker before loading.