How to use the Volumetric Weight Calculator
- Measure the outer length, width and height of the packed box at the widest points.
- Pick the unit and your carrier's divisor (5000 is most common for couriers).
- Enter the number of identical boxes and, optionally, the total actual weight.
Formula
Volumetric weight (kg) = Length × Width × Height (cm) ÷ Divisor
For inches: convert each dimension to cm first (1 in = 2.54 cm)
Chargeable weight = the higher of actual weight and volumetric weight
What volumetric weight is
Volumetric (or dimensional) weight converts the space a parcel occupies into a weight, so that bulky but light items pay fairly for the room they take in a van or aircraft. The carrier compares it with the actual weight and charges the higher one — the chargeable weight.
Which divisor to use
| Divisor | Commonly used for | 1 kg equals |
|---|---|---|
| 5000 | Most domestic and international express couriers | 5,000 cm³ |
| 6000 | Air cargo (IATA standard) and some couriers | 6,000 cm³ |
| 4000 | Some surface / road services | 4,000 cm³ |
A smaller divisor produces a higher volumetric weight. Always confirm the divisor and rounding rules on your carrier's rate card.
How to reduce volumetric weight
- Use the smallest box that protects the item — a few centimetres on each side adds up quickly.
- Ship flat-packed or compressed items where possible.
- Combine small items into one well-filled carton instead of several half-empty ones.
Worked examples
A 50 × 40 × 30 cm box weighing 9.5 kg, divisor 5000
- Volume = 50 × 40 × 30 = 60,000 cm³
- Volumetric weight = 60,000 ÷ 5,000 = 12 kg
- Chargeable weight = higher of 9.5 kg and 12 kg
Billed on 12 kg (volumetric)
The same box by air cargo (divisor 6000)
- Volumetric weight = 60,000 ÷ 6,000 = 10 kg
Billed on 10 kg
Important notes
- Carriers usually round the chargeable weight up to the next 0.5 kg or 1 kg slab. Choose the rounding that matches your carrier.
- Measure the packed box, including any bulges; carriers re-measure at the hub.
Frequently asked questions
What is the formula for volumetric weight?
Length × width × height in centimetres, divided by the carrier's divisor (commonly 5000). A 40 × 30 × 20 cm box is 24,000 cm³ ÷ 5,000 = 4.8 kg.
Why is my courier charging more than the actual weight?
Because the parcel's volumetric weight is higher than its actual weight, and couriers bill whichever is higher.
What is CBM?
Cubic metres — the volume used for freight and container shipping. The calculator shows total CBM for your boxes. 1 CBM = 1,000,000 cm³.