DimWeight Calc › CBM
CBM calculator (cubic meters & chargeable weight)
Enter the carton size, weight and number of cartons. You get the total CBM and cubic feet, and the chargeable quantity for sea LCL, air cargo or express.
Calculations run entirely in your browser – the sizes and weights you type are never sent to a server.
CBM rules and sources
| 1 CBM | 1 m³ = 1,000,000 cm³ (SI). 1 ft³ = 1,728 in³ = 0.028317 m³. |
|---|---|
| Sea LCL (W/M) | Freight ton = the larger of metric tons and cubic metres – 1 CBM counts as 1,000 kg [C1, C2]. Minimum charge and rounding are set by each forwarder (no single authoritative rule) – not applied here. |
| Air cargo | cm³ ÷ 6,000 = kg (1 CBM ≈ 166.67 kg) [C3, C4]. IATA TACT Rules text is paid and could not be read. |
| Express | cm³ ÷ 5,000 = kg (1 CBM = 200 kg) – DHL Express [D1–D3], FedEx UK [F3]. |
Sources (checked ):
- UN/CEFACT unit codes – A75 freight ton [C1, official]
- NVOCC Rules Tariff sample (LCL per CBM up to 1000 kg per CBM) [C2, third-party]
- Air China group – General Conditions of Cargo Carriage 1.21 (from Jan 1, 2025) [C3, official]
- IATA Knowledge Hub – Air cargo tariffs and rules [C4, official]
- DHL – Get a rate quote and transit time [D1, official]
- FedEx UK rates (effective 2 January 2023 – older document) [F3, official]
Worked example
- Two cartons of 120 × 100 × 80 cm, 150 kg each: 1.2 × 1.0 × 0.8 m × 2 = 1.92 CBM (67.8 ft³).
- Sea LCL: weight 0.3 t vs 1.92 CBM → 1.92 W/M.
- Air: 320 kg volumetric vs 300 kg gross → 320 kg chargeable. Express (÷5,000): 384 kg.
FAQ
How do I calculate CBM?
Multiply length × width × height in metres, then by the number of cartons. In centimetres, divide the product by 1,000,000.
What is W/M in sea freight?
Weight or measurement: the forwarder charges the larger of the weight in metric tons and the volume in CBM, so 1 CBM is treated like 1,000 kg.
How many kg is 1 CBM in air freight?
With the common ÷6,000 rule, 1 CBM is about 166.67 kg. Express carriers using ÷5,000 count 1 CBM as 200 kg.
Is there a minimum CBM?
Many forwarders set a minimum (often 1 CBM) and their own rounding, but there is no single official rule, so check your quote.