Volumetric Weight Calculator: The Short Answer
A brand needs 50 cartons of hoodies by air to catch a launch date. Each carton is 60 × 40 × 40 centimetres and weighs 12 kilograms, so the shipment weighs 600 kilograms on the scales. The airline does not bill on 600. It converts each carton to a volumetric weight by multiplying the dimensions and dividing by 6,000, which gives 16 kilograms a carton, 800 kilograms in all, and bills the greater of the two. This volumetric weight calculator does that conversion for you and shows how much extra you are paying for space.
The lesson is the same for almost every garment shipment: you are paying for the volume of the cartons, not just the weight of the clothes. That makes carton size, folding and packing the biggest levers you control, and it is why a volumetric weight calculator is worth opening before you commit to air.
It also explains why two quotes for apparently identical orders can differ. If one supplier packs hoodies into taller cartons or leaves a few centimetres of slack, the volumetric weight rises even though the garments are the same. Comparing quotes on chargeable weight, rather than on the weight of the goods, puts them on the same footing and shows whether a difference comes from the rate or from the packing.
Use the Volumetric Weight Calculator for Clothing Cartons
Enter the outside dimensions of one carton in centimetres, the number of cartons, the gross weight of one carton and the divisor your carrier uses. The volumetric weight calculator returns the volumetric weight per carton and for the whole shipment, the actual weight and the chargeable weight, which is the greater of the two. If you have an air freight rate per kilogram, add it to see the estimated cost.
Volumetric weight calculator
Volumetric, actual and chargeable weight
Carriers set their own divisors and rounding rules, so confirm them in the quote. This is an estimate of the chargeable weight, not a rate quotation.
The table below the result converts the same cartons to other freight measures, so you can compare air with sea at a glance. The sea figure is the greater of the volume in cubic metres and the weight in tonnes, which for garments is nearly always the volume.
Work through a few variations before you accept a packing plan. Change the height by five centimetres, switch the divisor from 6,000 to 5,000, or split the same pieces across more, smaller cartons. Each change moves the chargeable weight, and the volumetric weight calculator shows by how much, which is far easier than discovering it on an invoice.
How Volumetric Weight Is Calculated
Volumetric weight turns space into an equivalent weight so that carriers can price bulky and dense cargo on the same scale. For air freight the usual formula multiplies length, width and height in centimetres and divides by 6,000, which gives kilograms. That divisor is equivalent to 167 kilograms for every cubic metre. Some express carriers use a divisor of 5,000, which is the same as 200 kilograms per cubic metre and charges more for the same carton. The carrier's terms decide which applies, and the trade body IATA is where the air cargo industry publishes its standards.
From carton to chargeable weight
- 1Measure the cartonLength, width and height in cm, outside, as packed.
- 2MultiplyLength × width × height gives cubic centimetres.
- 3DivideDivide by 6,000 (or the carrier's divisor) for kg.
- 4CompareSet the result against the actual gross weight.
- 5Take the greaterThe greater of the two is the chargeable weight.
Round the dimensions up and apply the formula to every carton, not to the shipment as a whole, because carriers usually measure and round carton by carton. A rounding rule can add a kilogram or two to each one, and across 50 cartons that adds up.
Conversion Factors for Air, Sea and Road
The same cubic metre is charged differently depending on how it travels. The table sets out the equivalent weights that are commonly used, so you can see why air freight punishes bulky goods far more than sea.
How one cubic metre converts to chargeable weight
| Mode | Common conversion | Equivalent weight of 1 CBM | What it means for garments |
|---|---|---|---|
| Air freight | 1 CBM = 167 kg (divisor 6,000) | 167 kg | Cartons of light garments are charged on volume |
| Air express (some carriers) | Divisor 5,000 | 200 kg | Higher charge for the same carton |
| Road freight | 1 CBM = about 333 kg | 333 kg | Volume still tends to decide for garments |
| Sea freight, LCL | 1 CBM = 1,000 kg | 1,000 kg | Volume decides almost every time |
Conversions as commonly published by freight forwarders; your carrier's terms prevail. Check them on the quote before you rely on them.
The gap between 167 kilograms and 1,000 kilograms per cubic metre is why garments are so rarely worth sending by air unless time is critical. Our guide to sea freight versus air freight for clothing weighs time against cost for the common situations.
Which Wins: Volume or Weight?
Whether volume or weight decides the bill depends on how densely the carton is packed. A carton of folded T-shirts is mostly air, so volume wins. A carton of heavy denim or a dense roll of fabric can weigh more than its volumetric weight, so weight wins. The table shows five carton sizes, with weights chosen to illustrate the difference.
Chargeable weight for five carton examples at a 6,000 divisor
| Carton size (cm) | Actual weight | Volumetric weight | Chargeable weight | What decides |
|---|---|---|---|---|
| 50 × 40 × 30 | 8 kg | 10.0 kg | 10.0 kg | Volume |
| 60 × 40 × 40 | 12 kg | 16.0 kg | 16.0 kg | Volume |
| 60 × 40 × 40 | 22 kg | 16.0 kg | 22.0 kg | Weight |
| 70 × 50 × 40 | 15 kg | 23.3 kg | 23.3 kg | Volume |
| 80 × 60 × 50 | 20 kg | 40.0 kg | 40.0 kg | Volume |
Illustrative carton sizes and weights. Volumetric weight = length × width × height ÷ 6,000; chargeable weight is the greater of actual and volumetric.
Most clothing cartons sit in the volumetric camp, which means a few centimetres of carton height can matter more than a kilogram of garments. If your product is dense, such as heavyweight denim, check both figures rather than assuming.
The third row of the table shows the crossover. The carton is the same size as the second row, but at 22 kilograms the actual weight overtakes the volumetric weight, so weight decides. Packing more garments into a carton raises its weight without raising its volume, which is one reason a well-filled carton is cheaper per piece to fly than a half-empty one.
What Volume Costs You in the Example
The pie shows how much of the 800 chargeable kilograms in the example is real weight and how much is space. A quarter of what you pay for is the volume of the cartons, not the clothes inside them.
Illustrative split of 800 chargeable kg for 50 cartons
- Actual weight of the cartons (600 kg)75%
- Extra charged for volume (200 kg)25%
Illustrative arithmetic from the calculator default: 50 cartons of 60 × 40 × 40 cm at 12 kg actual and 16 kg volumetric each.
Every kilogram in the second slice is paid for but carries nothing. Shrinking the carton, packing more garments into the same space or compressing polybagged items are the practical ways to reduce it. Our CBM calculator for clothing cartons shows the same effect in cubic metres.
How Carton Height Changes the Bill
Height is the easiest dimension to change, because cartons are cut to size and garments are often packed to the height of the stack. The chart holds length, width and quantity constant and shows the total volumetric weight of 50 cartons as the carton height rises from 30 to 60 centimetres.
Total volumetric weight of 50 cartons (60 × 40 cm base) by carton height
Volumetric kilograms
Illustrative arithmetic: 60 × 40 × height ÷ 6,000 per carton, multiplied by 50. Actual weight is not shown.
Each extra ten centimetres of height adds 200 volumetric kilograms to the shipment. If the extra height is empty space, you are paying a premium for it. A volumetric weight calculator makes the cost visible before the cartons are cut, when it is cheap to change.
Ways to Reduce Chargeable Weight
Because volume sets the bill, saving weight on the garment hardly helps. What helps is saving space. A short list of habits, agreed with your supplier before packing, can cut chargeable weight without touching quality.
Practical ways to reduce volumetric weight
- Choose carton dimensions that fit the folded garment stack closely
- Fold and bag garments to the same size so they stack without gaps
- Ask whether a compression pack is acceptable for the product
- Avoid half-empty cartons by planning pieces per carton in advance
- Combine shipments only when it fills cartons, not when it adds air
- Ask the carrier which divisor and rounding rules apply
Garment protection and presentation must not be compromised. Agree any packing change with your supplier first.
Once you know the chargeable weight, carry it into the shipping cost per garment calculator to see what air costs each piece, and then into your landed cost. Forwarders and their international federation FIATA can advise on options and routes.
How Ruhrose Helps You Plan Packing
Ruhrose develops hoodies, fleece, jersey, denim and woven casualwear for UK buyers, with production in Bangladesh. We can talk through carton sizes, folding and pieces per carton during development, so the volumetric weight of an urgent shipment is known before packing, not after. Our guide to clothing production lead times explains when air freight becomes a realistic option, and Ruhrose's clothing manufacturing pages describe what we make.
Before you book air freight, ask yourself one question: are you paying to move garments, or to move air?