Lesson 16 · Export & merchandising
Freight: CBM, cartons and containers
6 min
In a real company
Shipping executive, export merchandiser, logistics
Sea freight is charged on volume (CBM). Knowing carton CBM tells you the freight per piece and whether you need a 20 ft or 40 ft container.
Key ideas
- CBM per carton = L × W × H in cm ÷ 1,000,000.
- Sea freight = total CBM × rate per CBM.
- A 20 ft container holds about 28–33 CBM usable; a 40 ft about 58–67 CBM.
- Air freight uses the higher of actual and volumetric weight.
Formula
- CBM / carton
- = L × W × H (cm) ÷ 1,000,000
- Total CBM
- = CBM / carton × Cartons
- Sea freight
- = Total CBM × Rate
Worked example
417 cartons of 60 × 40 × 35 cm, 24 pcs per carton, sea freight $55 per CBM.
- 1CBM / carton = 60 × 40 × 35 ÷ 1,000,000 = 0.084
- 2Total = 0.084 × 417 = 35.03 CBM
- 3Freight = 35.03 × 55 = $1,926.54 → $0.192 per piece
✅ 35 CBM — more than a 20 ft container; about $0.19 freight per piece.
Try it live in the calculatorCommon mistakes
- Measuring the carton's inside instead of outside dimensions.
- Forgetting pallets in CBM.
- Using actual weight for air freight when volumetric is higher.
Quick quiz
Answer 2 of 3 correctly to complete the lesson.
1. CBM of a 50 × 40 × 30 cm carton?
2. 500 cartons × 0.06 CBM at $50/CBM = ?
3. Sea freight is mainly charged on…