Shipping costs
Volumetric vs actual weight: calculate a multiple-box shipment
By PORTADOR editorial team · Published
PORTADOR compares the total actual weight with the total volumetric weight of the shipment. The higher total is the chargeable weight. Each box's volumetric weight is length × breadth × height in centimetres ÷ 5,000; identical boxes are multiplied by quantity.
What the two weights measure
Actual weight is the packed shipment's mass on a scale. Volumetric weight expresses how much space the packaging occupies using a shipping divisor. A light, large carton can have a volumetric weight above its scale weight, while a compact carton of dense components can have a higher actual weight.
Use the dimensions of the finished outer packaging. Measuring the product alone leaves out the carton, cushioning, crate or pallet. PORTADOR's calculator uses centimetres and kilograms. Enter 50 for a 50-centimetre length, rather than 0.5 metres or 500 millimetres.
A two-box example, from measurements to totals
Box 1 measures 50 × 40 × 30 cm and weighs 7 kg. Its volumetric weight is 50 × 40 × 30 ÷ 5,000 = 12 kg. Box 2 measures 10 × 10 × 50 cm and weighs 10 kg. Its volumetric weight is 1 kg.
The shipment therefore has 17 kg actual weight and 13 kg volumetric weight. PORTADOR's shipment-total comparison gives a chargeable weight of 17 kg. Adding each box's separate maximum would produce 22 kg, which is not the shipment-total rule used by this calculator.
If three boxes are identical to Box 1, enter its dimensions and 7 kg actual weight once, then set quantity to 3. The calculator shows 21 kg actual and 36 kg volumetric for that box type. Add a separate row whenever the dimensions or actual weight differ.
Measure consistently before asking for a quote
A useful weight estimate begins after packing. Measure the longest outside extent along each dimension, including bulges or protrusions, and weigh each packed box. If a crate or pallet is needed, confirm with the operations team how the complete handling unit will be measured.
Do not reduce dimensions on paper to obtain a lower estimate. Re-measure after any packing change. Reducing unnecessary empty space can change volumetric weight, but product protection, handling requirements and cargo acceptance come first.
- Use a separate box row for every different combination of dimensions and actual weight.
- Use quantity only for genuinely identical packed boxes.
- Keep measurements in centimetres and scale weights in kilograms.
- Retain a packing list so the quote and the collected shipment can be checked against the same information.
Chargeable weight is not the final price
A weight calculation does not establish a rate, confirm serviceability or reserve airline capacity. The shipment's route, service, pickup and delivery arrangements, handling requirements and agreed commercial terms also matter. Minimum charges and billing increments, if applicable, belong to the agreed tariff; the calculator does not invent or apply them.
The 5,000 divisor is the PORTADOR rule specified for this calculator. Do not assume every carrier or every service uses the same divisor or multi-piece aggregation method. When comparing quotations, ask each provider to identify its measurement and billing basis.
Send an enquiry that can be assessed
Alongside the calculated totals, share origin and destination PIN codes, the cargo description, box count, packed measurements and the required arrival time. Explain any special handling or packing constraints before collection. The team can then assess the shipment against the requested service.
Use the calculator below to check your own boxes. Its results stay in the page until you clear or leave it; calculating a weight does not create a booking or change a shipment record.