The number of slabs in a container depends on their size and thickness, because slabs fill a container by weight long before they fill its space. The packing frames take part of the weight limit too.
There is no fixed number. Use the method below to estimate it, then ask the factory for its loading plan, which gives the real figure for your size, thickness and packing.
Step 1: Weight per slab
Porcelain weighs roughly 2.3 to 2.5 kg per square metre for each millimetre of thickness. Multiply that by the thickness, then by the slab's area.
- An 800x1600 mm slab covers 1.28 m². At 9 mm it weighs very roughly 27 to 29 kg.
- A 1200x2400 mm slab covers 2.88 m². At 9 mm it weighs very roughly 60 to 65 kg; at 15 mm, roughly 100 to 108 kg.
- A 1600x3200 mm slab covers 5.12 m². At 12 mm it weighs very roughly 140 to 155 kg.
Use the factory's figures
Always replace these estimates with the factory's stated weight per slab, because body mix and backing differ.
Step 2: Add the packing
A-frames and crates are heavy. Steel frames and solid timber crates can add a noticeable share to each load. Ask the factory for the empty weight of each frame or crate and the number of slabs it holds. See how large slabs are packed for the packing types.
Step 3: Divide into the payload
A 20 ft container's usable payload is often around 26 to 28 tonnes, depending on the shipping line, the container and the route. Road weight limits at either end can lower it further. Our guide on the maximum payload for a tile container explains these limits.
As an illustration only: if a loading plan allows about 24 tonnes of slabs after the frames, 9 mm slabs of 1200x2400 mm would come to somewhere around 370 to 400 slabs. That is roughly 1,050 to 1,150 m². Your factory's plan may differ.
Step 4: Check the space
Weight is usually the limit, but not always. Very large slabs on A-frames can run out of floor space or door height before they reach the payload, especially with thin slabs. A 1600x3200 mm slab on edge needs frames long enough to support it, and the frames must fit through the doors.
Thin 6 mm slabs also weigh less per square metre, so you may fit more square metres than with thicker slabs, until the frames fill the floor.
What to ask the factory for
- Weight per slab and gross weight per frame or crate.
- Slabs and square metres per frame or crate.
- A loading plan showing frames or crates per container and total gross weight.
- Confirmation that the plan respects the shipping line's limit and the road limits at both ends.
Slabs and tiles together
If you also buy tiles, the same logic for tiles is in square metres of tiles in a 20 ft container.
Next step
We check the factory's loading plan against weight limits before production and supervise the loading itself. To plan containers for your slab range, book a free sourcing review.