How to Calculate Volumetric Weight and CBM (With Examples)

The short answer

Express couriers and air freight carriers bill on chargeable weight:

• Volumetric weight (kg) = length (cm) × width (cm) × height (cm) ÷ divisor
• Chargeable weight = the higher of actual gross weight and volumetric weight

A light but bulky carton is billed on its volume; a small, dense one on its actual weight. To skip the arithmetic, open the volumetric weight and CBM calculator and enter the dimensions and weight.

Which divisor: 5000 or 6000?

The carrier sets the divisor. Two are common:

DHL states that most international express shipments use L × W × H (cm) ÷ 5000 and are charged on the greater of actual and volumetric weight. Air freight forwarders usually quote with 6000. A smaller divisor gives a higher volumetric weight, so the same carton costs about 20% more at 5000 than at 6000. Always check your rate card; negotiated contracts sometimes use a different factor.

Worked example

One carton, 40 × 30 × 20 cm, gross weight 3 kg:

1. Volume = 40 × 30 × 20 = 24,000 cm³ = 0.024 m³ (CBM)
2. At 5000: 24,000 ÷ 5000 = 4.8 kg
3. At 6000: 24,000 ÷ 6000 = 4.0 kg
4. Chargeable weight: 4.8 kg by express, 4.0 kg by air cargo (both above the 3 kg actual weight)

How to calculate CBM

CBM (cubic meters) is the unit for sea freight and container planning:

• CBM = length (m) × width (m) × height (m) × number of cartons
• From centimeters: L × W × H ÷ 1,000,000
• 1 m³ ≈ 35.315 cubic feet

Less-than-container (LCL) sea freight is usually charged weight-or-measure (W/M): one cubic meter is compared with one metric ton and the larger figure is billed. For full containers, estimate how many cartons fit in a 20GP, 40GP or 40HQ with the container loading calculator, or use the pallet and container fill calculator for palletized cargo.

Multiple cartons and rounding

• Per piece or per shipment: some carriers calculate and round each piece, then add them up; others total the shipment first. Your contract says which.
• Rounding: chargeable weight is often rounded up to the next 0.5 kg or 1 kg, and minimum charges vary by carrier.
• Measure the outermost points, including bulges and handles. Under-declared dimensions get re-measured at the hub and re-billed.

The calculator handles multiple cartons, inches and pounds, custom divisors and rounding rules, and exports a per-carton breakdown.

How to lower chargeable weight

1. Fit the box to the product instead of using the next standard size up.
2. Ship knock-down or nested where the product allows it, for example packing a fan impeller separately from its housing.
3. Move bulky cargo to sea or road when volumetric weight is far above actual weight.
4. Price the whole landed cost before quoting: compare FOB, CIF and DDP with the landed cost calculator.

Source

• DHL: How to calculate volumetric weight