CBM to Weight Calculator
Accurate Freight Volume & Chargeable Weight Calculation
Select the shipping method to apply the correct volumetric divisor.
Actual scale weight per single carton/pallet.
Chargeable Weight
This is the billable weight for your shipment
Shipment Breakdown
| Metric | Per Unit | Total Shipment |
|---|---|---|
| Volume (CBM) | 0 | 0 |
| Gross Weight | 0 | 0 |
| Volumetric Wgt | 0 | 0 |
Weight Comparison Chart
What is a CBM to Weight Calculator?
A CBM to Weight Calculator is an essential logistics tool used by importers, exporters, and freight forwarders to determine the billable weight of a shipment. In the world of international shipping, carriers do not simply charge based on the dead weight (actual mass) of the cargo. Instead, they consider the space the cargo occupies—its volume.
This calculator helps you compute the Cubic Meter (CBM) volume of your goods and converts it into Volumetric Weight (also known as Dimensional Weight). The freight carrier will charge you based on whichever is higher: the actual gross weight or the volumetric weight. This is known as the Chargeable Weight.
Understanding this calculation is crucial for budgeting shipping costs accurately, optimizing packaging efficiency, and avoiding unexpected fees from carriers.
CBM Formula and Mathematical Explanation
The calculation involves two main steps: determining the volume in CBM and then applying a "freight factor" or "divisor" to find the volumetric weight.
Step 1: Calculate Volume (CBM)
The basic formula for CBM is:
Length (m) × Width (m) × Height (m) = CBM (m³)
If you measure in centimeters (cm), the formula is:
(Length cm × Width cm × Height cm) ÷ 1,000,000 = CBM
Step 2: Calculate Volumetric Weight
Once you have the CBM, you multiply it by a standard industry conversion factor depending on the mode of transport:
- Air Freight: 1 CBM ≈ 167 kg (or divide cm³ volume by 6000)
- Sea Freight: 1 CBM ≈ 1000 kg (1 ton)
- Road Freight: Varies, often 1 CBM ≈ 333 kg (or divide cm³ volume by 3000)
- Courier (Express): 1 CBM ≈ 200 kg (or divide cm³ volume by 5000)
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| L, W, H | Dimensions of package | m, cm, in | 0.1m – 3.0m |
| CBM | Cubic Meter Volume | m³ | 0.01 – 60.0+ |
| DIM Factor | Density Ratio | kg/m³ | 167 (Air), 1000 (Sea) |
| Chargeable Wgt | Billable Weight | kg | > 0 |
Practical Examples (Real-World Use Cases)
Example 1: Air Freight Shipment
Imagine you are shipping 5 boxes of electronic components via Air Freight.
- Dimensions: 50cm x 40cm x 30cm per box
- Actual Weight: 8 kg per box
- Quantity: 5 boxes
Calculation:
- Volume per box = 50 * 40 * 30 = 60,000 cm³ = 0.06 CBM
- Total Volume = 0.06 * 5 = 0.30 CBM
- Volumetric Weight (Air): 0.30 CBM * 167 = 50.1 kg
- Total Gross Weight: 8 kg * 5 = 40.0 kg
Result: Since 50.1 kg (Volumetric) > 40.0 kg (Gross), the carrier charges for 50.1 kg.
Example 2: Sea Freight LCL
You are shipping 2 pallets of machinery parts via Sea Freight (LCL).
- Dimensions: 120cm x 100cm x 100cm per pallet
- Actual Weight: 600 kg per pallet
- Quantity: 2 pallets
Calculation:
- Volume per pallet = 1.2 * 1.0 * 1.0 = 1.2 CBM
- Total Volume = 2.4 CBM
- Volumetric Weight (Sea): 2.4 CBM * 1000 = 2400 kg
- Total Gross Weight: 600 kg * 2 = 1200 kg
Result: In sea freight, you are often billed "Weight or Measure" (W/M). Here, the volume equivalent (2.4 tons) is higher than the weight (1.2 tons). You will be charged based on 2.4 CBM / 2400 kg.
How to Use This CBM to Weight Calculator
- Select Transport Mode: Choose Air, Sea, Road, or Courier. This automatically updates the density divisor used in the formula.
- Choose Unit: Select whether your measurements are in Centimeters (cm), Meters (m), or Inches (in).
- Enter Dimensions: Input the Length, Width, and Height of a single carton or handling unit.
- Enter Quantity: Input the total number of identical units you are shipping.
- Enter Gross Weight: Input the actual scale weight of a single unit.
- Review Results: The calculator will instantly display the Total CBM, Volumetric Weight, and highlight the Chargeable Weight. Use the chart to visualize the difference between actual and volumetric weight.
Key Factors That Affect CBM Calculation Results
- Transport Mode Factors: The conversion factor (e.g., 167 for Air vs 1000 for Sea) drastically changes the result. Air cargo space is expensive, so light, bulky items are penalized more heavily.
- Packaging Efficiency: Excessive packaging or non-stackable shapes increase volume without adding value. Reducing box size by even 2cm can significantly lower chargeable weight in air freight.
- Palletization: If you palletize loose cartons, you must include the pallet dimensions (usually adding 15cm to height) and weight in your calculation.
- Carrier Specific Divisors: While 6000 is standard for air, some express couriers use 5000, which results in a higher billable weight. Always check with your specific forwarder.
- Measurement Units: Rounding errors when converting between inches and cm can add up across large shipments. Always measure precisely.
- Stackability: If your cargo is marked "Do Not Stack," carriers may charge you for the vertical space above your pallet up to the ceiling of the container or aircraft, effectively increasing your chargeable CBM.
Frequently Asked Questions (FAQ)
Q: What is the difference between Net Weight and Gross Weight?
A: Net weight is the weight of the product alone. Gross weight includes all packaging, pallets, and protective materials. Logistics calculations always use Gross Weight.
Q: Why is my chargeable weight higher than my scale weight?
A: This happens when your cargo is "low density" (bulky). The carrier charges for the space occupied because the plane/truck fills up in volume before it reaches its weight limit.
Q: Is the divisor always 6000 for air freight?
A: Typically yes, for international air freight. However, some domestic couriers or express services use 5000, which increases the volumetric weight calculation.
Q: How do I calculate CBM for cylindrical objects?
A: Logistics carriers generally treat cylinders as rectangles. You measure the diameter as both the Length and Width, and the length of the cylinder as the Height. (Diameter x Diameter x Length).
Q: Does this calculator support inches and pounds?
A: Yes. Select "Inches (in) / Pounds (lb)" in the unit selector. The calculator handles the conversion to metric CBM and kg internally for standardization.
Q: What is a Revenue Ton?
A: In sea freight, a Revenue Ton is the unit used to calculate freight charges, derived from whichever is greater: 1 ton (1000 kg) or 1 cubic meter (CBM).
Q: Can I use this for container loading?
A: This calculator gives you the total volume. A 20ft container holds approx 33 CBM, and a 40ft holds approx 67 CBM. However, due to wasted space between boxes, usable capacity is usually 10-15% less.
Q: How can I reduce my chargeable weight?
A: Optimize packaging to reduce empty space, vacuum seal soft goods, or disassemble items to reduce the overall dimensions.
Related Tools and Internal Resources
- Freight Class Calculator – Determine NMFC codes and classes for LTL shipping.
- Container Loading Calculator – Optimize how many pallets fit in a 20ft or 40ft container.
- Import Duty Calculator – Estimate landed costs including taxes and tariffs.
- Cargo Density Calculator – Calculate density in kg/m³ or lbs/ft³.
- Pallet Configurator – Best ways to stack cartons on a standard ISO or EUR pallet.
- Incoterms 2024 Guide – Understand buyer vs seller responsibilities (EXW, FOB, CIF).