Freight-Specific Conversions
IATA volumetric: 1 CBM = 166.67 kg (divisor 6000). The higher of actual weight vs volumetric weight is chargeable.
W/M rule: 1 CBM = 1 freight tonne (revenue tonne). Carrier charges whichever is greater — 1 CBM or 1,000 kg.
Air carriers charge on whichever is higher. Use our dedicated calculator for multi-piece shipments with different dimensions.
Chargeable Weight Calculator →Convert Any Unit
Weight Conversions
| From | To | Factor |
|---|---|---|
| 1 kg | 2.20462 lbs | × 2.20462 |
| 1 tonne | 2,204.62 lbs | × 2,204.62 |
| 1 tonne | 1.10231 short tons (US) | × 1.10231 |
| 1 tonne | 0.984207 long tons (UK) | × 0.984207 |
| 1 lb | 0.453592 kg | × 0.453592 |
| 1 short ton | 907.185 kg | × 907.185 |
Volume Conversions
| From | To | Factor |
|---|---|---|
| 1 CBM | 35.3147 ft³ | × 35.3147 |
| 1 CBM | 61,023.7 in³ | × 61,023.7 |
| 1 CBM | 1,000 litres | × 1,000 |
| 1 litre | 0.264172 US gal | × 0.264172 |
| 1 litre | 0.219969 UK gal | × 0.219969 |
Length Conversions
| From | To | Factor |
|---|---|---|
| 1 cm | 0.393701 inches | × 0.393701 |
| 1 m | 3.28084 feet | × 3.28084 |
| 1 m | 39.3701 inches | × 39.3701 |
| 1 inch | 2.54 cm | × 2.54 |
| 1 foot | 30.48 cm | × 30.48 |
Understanding Chargeable Weight
Air freight carriers charge on whichever is higher: actual gross weight or volumetric weight. Volumetric weight is calculated by dividing the cubic centimetre volume by a divisor (6,000 for IATA standard, 5,000 for express couriers). Light, bulky cargo always pays on volume. Use our chargeable weight calculator for multi-piece shipments.
The W/M Rule in Sea Freight
Ocean carriers price per “freight tonne” (revenue tonne) using the W/M rule — Weight or Measurement, whichever yields higher revenue. 1 freight tonne = 1 CBM or 1,000 kg. A 2 CBM shipment weighing 500 kg pays for 2 freight tonnes (volume-based). A 0.5 CBM shipment weighing 2,000 kg pays for 2 freight tonnes (weight-based). Use our CBM calculator to get the volume side.
Metric vs Imperial in Global Freight
European and Asian trade uses metric (kg, cm, CBM). The US uses imperial (lbs, inches, cubic feet). Sea freight quotes in CBM and metric tonnes; US domestic trucking quotes in lbs and cubic feet. Mismatched units cause quoting errors, customs holds, and carrier surcharges.
Common Freight Conversion Mistakes
Short tons vs long tons vs metric tonnes — Short tons (2,000 lbs / 907 kg) are used in US domestic freight. Long tons (2,240 lbs / 1,016 kg) appear in UK bulk commodities. Metric tonnes (2,204 lbs / 1,000 kg) are the international standard. Confusing these causes billing disputes of 10% or more.
US gallons vs UK imperial gallons — A US gallon is 3.785 litres; a UK imperial gallon is 4.546 litres. When shipping liquids, always confirm which gallon your trading partner means.
Frequently Asked Questions
How do I calculate chargeable weight for air freight?
What is a freight tonne?
What is a short ton vs a long ton?
How do I convert CBM to cubic feet?
GET /api/convert?value=10&from=cbm&to=chargeable_kgConversion factors are standard mathematical constants. Freight-specific calculations use IATA standard divisor (6000). Always verify unit requirements with your carrier or customs authority.