Pallets per Container Calculator (20ft / 40ft)

Understanding the pallets per container calculator — concept and principle

Before booking a container, shippers need to know how many pallets fit on its floor. This calculator takes a pallet's length and width and the inside dimensions of a 20 ft or 40 ft dry container, counts whole pallets in one layer (both orientations and a simple mixed layout) and shows the double-stacked count.

How it is calculated

With pallet length a, width b and container inside length L and width W (all in mm):

• Lengthwise: ⌊L ÷ a⌋ × ⌊W ÷ b⌋, where ⌊ ⌋ means rounding down to a whole number.
• Crosswise: ⌊L ÷ b⌋ × ⌊W ÷ a⌋ (pallets turned 90°).
• Mixed layout: for each possible number i of lengthwise rows, place i × ⌊W ÷ b⌋ pallets and fill the leftover length L − i × a with turned pallets, ⌊(L − i·a) ÷ b⌋ × ⌊W ÷ a⌋. The same is tried across the width and starting with either orientation; the best total is kept.
• Double-stacked: best single-layer count × 2.

The principle

Pallets cannot be cut, so only whole pallets count, which is why each division is rounded down. Turning part of the load can use space that a single orientation wastes. The calculator tries blocks of one orientation followed by the other, both along the length and across the width, which is how loaders fit 1,200 × 800 mm Euro pallets: 11 in a 20 ft and 25 in a 40 ft container.

Worked example

1. Inputs: pallet 1,100 × 1,100 mm (the T11 pallet common in Korea and Japan), 20 ft dry container with inside floor 5,898 × 2,352 mm.
2. Lengthwise: ⌊5,898 ÷ 1,100⌋ = 5 and ⌊2,352 ÷ 1,100⌋ = 2, so 5 × 2 = 10.
3. Crosswise: the pallet is square, so it is also 10.
4. Mixed layout: no combination beats 10, so best = 10 pallets single-stacked.
5. Double-stacked: 10 × 2 = 20.

How to read the result

The result is a floor-space limit. Two other limits may be lower: weight and height. Each container has a maximum payload and gross weight on its data plate, and dense cargo can reach the weight limit before the floor is full. A standard (not high-cube) dry container has an inside height of roughly 2.39 m, so double-stacking only works if two loaded pallets fit under it and the goods can bear the load.

Common mistakes

• Using outside container dimensions (for example 6,058 mm long for a 20 ft) instead of inside dimensions.
• Entering the pallet's base size when the goods overhang it; use the largest footprint of the loaded pallet.
• Assuming double-stacking is allowed for fragile or heavy goods.

Frequently asked questions

How many T11 pallets fit in a 20 ft container?

10 on the floor (5 rows of 2), or 20 if the cargo can be double-stacked.

How many T11 pallets fit in a 40 ft container?

20 on the floor.

Why might my forwarder's count differ from this tool?

Real plans also allow for door width, bracing, overhang and weight, and may use patterns this search does not try.

Sources: ISO 668, Series 1 freight containers: Classification, dimensions and ratings · ISO 1496-1, Series 1 freight containers: Specification and testing, Part 1 · ISO 6780, Flat pallets for intercontinental materials handling: Principal dimensions and tolerances