Choosing export carton dimensions to cut freight cost

Why a centimetre matters

Pallets and containers are filled in whole cartons. If a carton is a little too big, a whole row or a whole layer disappears. Compare a 40 × 30 × 20 cm carton with one just 1 cm larger in each direction:

The bigger carton holds about 11 % more volume each, but the pallet takes 46 % fewer cartons, so the goods per pallet fall sharply. Freight per unit rises accordingly.

Size cartons from the pallet down

1. Choose the pallet your buyer uses (EUR 1200 × 800, US 48 × 40 in, and so on).
2. Find carton footprints that divide it evenly, for example 40 × 30, 60 × 40 or 30 × 20 cm on a EUR pallet.
3. Choose the carton height so whole layers reach your height limit (often 1.6–1.8 m for sea, lower for air or racking).
4. Fit the product and its protection inside that outer size, not the other way round.
5. Check the result in the pallet calculator and the container calculator.

Outside dimensions, not inside

Corrugated board adds thickness: roughly 3–4 mm per wall for single wall and 6–7 mm for double wall. Carton makers often quote inside dimensions; your pallet plan needs the outside. Ask for both, and measure a sample.

Smaller is not always better

A smaller carton can fit more units per container: 39 × 29 × 19 cm cartons fit 3,472 in a 40HQ against 2,990 at 40 × 30 × 20. But more cartons mean more board, more labour and more labels, and each carton must still protect the product. Aim for the snuggest carton that passes your drop and stacking tests.

Checklist

• Outside dimensions divide the pallet footprint with no overhang.
• Whole layers reach the height limit with little wasted height.
• Gross weight per carton is safe for manual handling (many companies set limits around 20–25 kg).
• Board grade gives enough compression strength for the stack height.
• Shipping marks and handling symbols fit on the carton sides (see shipping marks).