CartonMath

Volumetric weight calculator

Volumetric weight is length × width × height divided by the carrier's divisor. A 40 × 30 × 20 cm box is 24,000 cm³, so it bills as 4.8 kg at 5000 or 4 kg at 6000, and you pay for whichever is higher: the actual or the volumetric weight.

Common divisors shown side by side. Check the one in your own carrier agreement.Updated

Link a result: ?l=40&w=30&h=20&wt=3.5&div=6000 or ?unit=in&l=12&w=12&h=12&wt=8&wu=lb&div=139

Parcel
cm
cm
cm
kg
pcs
Weight in
Divisor

5000 cm³/kg: common for international express. Check the divisor in your own carrier agreement.

Chargeable weight at 5000
4.8kg

Volumetric 4.8 kg is more than the actual 3.5 kg, so you are billed on volume.

Billed on volume
Volumetric
4.8 kg10.58 lb
Actual
3.5 kg7.72 lb
Volume
24,000 cm³0.024 m³, 1,465 in³

Every common divisor

Tap a row to use it
Volumetric and chargeable weight for every divisor
DivisorVolumetricChargeableBilled on

How volumetric weight works

The 40 × 30 × 20 cm example, line by line.

  1. Volume40 × 30 × 20 = 24,000 cm³
  2. Divide by 500024,000 ÷ 5000 = 4.8 kg
  3. Or by 600024,000 ÷ 6000 = 4 kg
  4. In inches24,000 ÷ 16.387 = 1,464.6 in³; ÷ 139 = 10.54 lb
  5. Actual weight3.5 kg
  6. Chargeable at 5000max(3.5, 4.8) = 4.8 kg

Why carriers charge for space

A van or aircraft hold fills up by volume as well as by weight. Volumetric (dimensional) weight turns a parcel's size into a weight, so a large, light parcel pays for the room it takes.

Divisors are a price, not a law of physics

A smaller divisor makes the same box heavier on paper. 4000 bills a box 25 % heavier than 5000, and 5000 bills it 20 % heavier than 6000. This calculator never assumes which divisor your carrier uses.

Multiple pieces

For a shipment of several pieces, the totals are compared. Some carriers compare per piece instead; check your terms if the pieces differ in size.

The common divisors

Different carriers and services use different divisors, and contracts can change them.

Common volumetric divisors
DivisorTypically seen withFormula
5000 cm³/kgCommon for international expressL × W × H in cm ÷ 5000 = kg
6000 cm³/kgCommon for many postal services and airlines (IATA 1:6000)L × W × H in cm ÷ 6000 = kg
4000 cm³/kgUsed by some express and courier servicesL × W × H in cm ÷ 4000 = kg
139 in³/lbCommon US domestic and international parcel divisorL × W × H in inches ÷ 139 = lb
166 in³/lbCommon for some US domestic and postal servicesL × W × H in inches ÷ 166 = lb

Volumetric weight by box size

Every common divisor worked out for popular carton sizes.

Open the full volumetric weight chart

Next steps

Common questions

How do you calculate volumetric weight?

Multiply length × width × height and divide by the carrier's divisor. In centimetres the answer is in kilograms (for example ÷ 5000 or ÷ 6000); in inches it is in pounds (for example ÷ 139 or ÷ 166). The carrier bills whichever is higher, the volumetric or the actual weight.

Which divisor does my carrier use?

Check your own rate card or carrier agreement. Divisors differ between carriers, services and countries and can be negotiated, so this calculator shows all the common ones side by side instead of assuming one.

What is the volumetric weight of a 40 × 30 × 20 cm box?

4.8 kg at the 5000 divisor, 4 kg at 6000 and 6 kg at 4000. In pounds it is 10.54 lb at 139 and 8.82 lb at 166.

Do carriers round the dimensions?

Many round each dimension, or the result, up before billing, for example to the next whole centimetre or inch, or the next half kilogram. Rounding rules are in your carrier's terms; this calculator shows the exact figure.

Is 1:6000 the same as 166.67 kg per cubic metre?

Yes. One cubic metre is 1,000,000 cm³, and 1,000,000 ÷ 6000 = 166.67 kg. In the same way the 5000 divisor equals 200 kg per m³ and 4000 equals 250 kg per m³.

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