How Many Ceramic Basins Fit in a 20GP / 40HQ Container? A Buyer’s Loading Calculator
Time:
2026-09-29
Author:
Goalar Export Team
Why buyers get the loading number wrong
Ceramic basins are shipped by volume, not by weight. A 40HQ container will hit its cubic limit long before it hits its 26-tonne payload. That single fact decides your freight cost per unit — and it is the number most buyers get wrong on the first order.
This guide gives you the formula, the real container dimensions, and a worked example you can apply to your own order.
Step 1 — Know the container you are actually buying
Shipping lines quote by "container" but the usable space is smaller than the nominal figure:
| Container | Internal volume (nominal) | Practical usable volume | Typical payload |
|---|---|---|---|
| 20GP (20 ft standard) | ~33.2 m³ | ~28 m³ | ~28,000 kg |
| 40GP (40 ft standard) | ~67.7 m³ | ~58 m³ | ~26,500 kg |
| 40HQ / 40HC (high cube) | ~76.4 m³ | ~68 m³ | ~26,000 kg |
The gap between nominal and practical comes from pallet voids, carton deformation, dunnage and the fact that cartons never tile a container perfectly. Always plan on practical volume, not nominal. In our own loading plans we quote the practical figure and keep a working margin, because the number you give your forwarder has to be the number you can stand behind when the container is closed.
Step 2 — Measure the carton, not the basin
This is where most quotes go wrong. A basin quoted as 610×465×150 mm travels in a carton that is larger — there is foam, corner protection and a plastic bag inside. Use the outer carton dimension:
Cartons per container = Practical usable volume ÷ Outer carton volume
Worked example (representative single-basin carton, 660 × 520 × 230 mm = 0.0789 m³):
| Container | Calculation | Cartons |
|---|---|---|
| 20GP | 28 ÷ 0.0789 | ≈ 354 |
| 40HQ | 68 ÷ 0.0789 | ≈ 861 |
Assumptions shown on purpose. A taller carton, a palletised load, or supplied packaging will change these numbers. Ask your supplier for the *outer carton* dimension and the *packing configuration* (how many pieces per carton) before you trust any loading figure.
Step 3 — The three factors that cut your number
- Palletisation. If you need floor-stacked pallets for a distribution centre, you can lose 8–15% of usable volume to pallet footprints and the gaps between them. Loose-loaded cartons always fit more.
- Mixed SKU orders. A one-model order stacks perfectly. A 6-SKU order with different carton heights creates voids — plan on a 5–10% penalty.
- Weight on heavy items. Wall-hung basins and full ceramic toilets are heavier. On a container loaded with heavy SKUs the constraint can flip from volume to mass before the cube runs out, and the loading plan has to be re-cut against the weight limit rather than the volume.
Step 4 — Turn cartons into cost per basin
The commercial question is not "how many fit" but "what does each one cost to land":
Freight per basin = Container freight rate ÷ Basins per container
If a 40HQ to Rotterdam costs USD X and carries ~861 single-basin cartons, the ocean freight contribution per basin is roughly X ÷ 861. Raising the loading quantity by 10% cuts that line by about 9% — often more than a supplier's price negotiation will win you.
What to ask your supplier before you book
Ask for these five things, and you can model any container yourself:
- Outer carton dimensions (L × W × H, in mm)
- Pieces per carton
- Gross weight per carton
- Recommended stacking limit under the carton
- Whether the load is loose or palletised
A supplier who can answer all five without going away to ask someone is a supplier who has actually shipped the product.
How to get an accurate number for your order
Send us your SKU list and destination port. We will return a loading plan with carton dimensions, pieces per container, gross weight and a container utilisation figure — built from the actual cartons, not a rule of thumb.

