Understanding the difference between gross weight, volumetric weight, and chargeable weight is essential for calculating shipping costs accurately. This guide explains each concept, provides formulas for air and sea freight, and includes worked examples.
The Three Weight Concepts
| Term | Definition | How Calculated |
|---|---|---|
| Gross Weight | Actual weight of cargo + packaging | Measured on a scale |
| Volumetric weight | Weight-equivalent of cargo volume | Calculated from dimensions ÷ divisor |
| Chargeable weight | Weight used for billing | Greater of gross or volumetric |
Carriers charge based on chargeable weight because they are limited by both weight (aircraft/container capacity) and space (volume). Light but bulky cargo is charged by volume; heavy but compact cargo is charged by actual weight.
Volumetric Weight Formulas by Mode
Air Freight (IATA Standard)
Volumetric Weight (kg) = (Length × Width × Height in cm) ÷ 6000
The divisor 6000 is the IATA standard for international air freight. Some domestic carriers use 5000.
Sea Freight LCL
Volumetric Weight (kg) = CBM × 1000
Or equivalently:
Volumetric Weight (kg) = (Length × Width × Height in meters) × 1000
The standard for LCL is 1 CBM = 1,000 kg. The chargeable weight is the greater of CBM × 1000 or actual gross weight.
Express Courier (DHL/FedEx/UPS)
Volumetric Weight (kg) = (Length × Width × Height in cm) ÷ 5000
Express couriers use a divisor of 5000, making volumetric weight higher than air freight's 6000.
Worked Examples
Example 1: Air Freight — Small Electronics Box
| Parameter | Value |
|---|---|
| Dimensions | 40 × 30 × 20 cm |
| Gross weight | 5 kg |
| Mode | Air freight |
Calculation: - Volumetric weight = (40 × 30 × 20) ÷ 6000 = 24,000 ÷ 6000 = 4.0 kg - Gross weight = 5.0 kg - Chargeable weight = max(4.0, 5.0) = 5.0 kg (charged by actual weight)
Example 2: Air Freight — Large but Light Box
| Parameter | Value |
|---|---|
| Dimensions | 80 × 60 × 40 cm |
| Gross weight | 15 kg |
| Mode | Air freight |
Calculation: - Volumetric weight = (80 × 60 × 40) ÷ 6000 = 192,000 ÷ 6000 = 32.0 kg - Gross weight = 15.0 kg - Chargeable weight = max(32.0, 15.0) = 32.0 kg (charged by volumetric weight — more than double actual!)
Example 3: LCL Sea Freight — Pallet of Goods
| Parameter | Value |
|---|---|
| Dimensions | 1.2 × 1.0 × 1.5 m |
| Gross weight | 350 kg |
| Mode | LCL sea freight |
Calculation: - CBM = 1.2 × 1.0 × 1.5 = 1.8 CBM - Volumetric weight = 1.8 × 1000 = 1,800 kg - Gross weight = 350 kg - Chargeable weight = max(1,800, 350) = 1,800 kg (charged by volume)
How to Reduce Chargeable Weight
- Optimize packaging: Use the smallest possible box that safely contains the product
- Remove excess air: Vacuum-seal soft goods, eliminate void fill
- Stack efficiently: Maximize pallet utilization within container dimensions
- Consider FCL for dense cargo: If chargeable weight exceeds ~12 CBM, FCL may be cheaper than LCL
For more on FCL vs LCL economics, see our FCL vs LCL Shipping Guide.
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Request a QuoteFAQ
Is volumetric weight the same as dimensional weight? Yes. "Volumetric weight," "dimensional weight," and "DIM weight" all refer to the same concept: weight calculated from cargo dimensions. Different industries use different terms.
Why does air freight use 6000 but express courier uses 5000? Express couriers (DHL, FedEx, UPS) use a more aggressive divisor (5000) because their network is more space-constrained. This means the same box will have a higher volumetric weight (and higher cost) via express courier than via air freight.
What is the W/M ratio in sea freight? W/M (Weight or Measure) is the LCL pricing basis. The carrier charges whichever is greater: weight in metric tons (W) or volume in CBM (M). The standard ratio is 1 CBM = 1,000 kg.
