Australia Post Cubic Weight Calculator
Australia Post cubic weight at 250 kg per cubic metre, the toughest factor of any major post, with the under-1 kg exemption and the courier alternatives.
Updated · By Niraj Kumar · 8 sources
https://checkpre.com/logistics/australia-post-cubic-weight-calculator
Box
Measure the packed box at its widest points, bulges included. UPS, FedEx and USPS round every fractional inch up.
Parcels are rated box by box; freight on the whole shipment.
Compare
- Dimensional weight
- 6 kg
- 40 × 30 × 20 cm ÷ 4,000
- Actual weight
- 3 kg
- Rounded up to the billing step
- Billed over actual weight
- 3 kg
- 100% more than the scale says
- Rank
- 7th lightest of 7
- International
- Lightest here
- Canada Post Regular Parcel
- 4 kg billable
Cut the height to 10 cm or less and Australia Post bills actual weight.
- 1Canada Post Regular Parcel÷ 6,0004 kg
- 2UPS Worldwide Express÷ 5,0005 kg
- 3FedEx International Priority÷ 5,0005 kg
- 4DHL Express Worldwide÷ 5,0005 kg
- 5Parcelforce Worldwide globalpriority÷ 5,0005 kg
- 6Canada Post Xpresspost / Priority÷ 5,0005 kg
- 7Australia Post Parcel Post÷ 4,0006 kg
| Service | Divisor | DIM weight | Actual | Billable, shipment | Billed on |
|---|---|---|---|---|---|
| Canada Post Regular Parcel | 6,000 | 4 kg | 3 kg | 4 kg | DIM weight |
| UPS Worldwide Express | 5,000 | 5 kg | 3 kg | 5 kg | DIM weight |
| FedEx International Priority | 5,000 | 5 kg | 3 kg | 5 kg | DIM weight |
| DHL Express Worldwide | 5,000 | 5 kg | 3 kg | 5 kg | DIM weight |
| Parcelforce Worldwide globalpriority | 5,000 | 5 kg | 3 kg | 5 kg | DIM weight |
| Canada Post Xpresspost / Priority | 5,000 | 5 kg | 3 kg | 5 kg | DIM weight |
| Australia Post Parcel Post | 4,000 | 6 kg | 3 kg | 6 kg | DIM weight |
How do carriers calculate dimensional weight?
Australia Post multiplies the parcel's length, width and height in metres by 250 to get cubic weight in kilograms, the same as dividing cubic centimetres by 4000. It charges cubic or actual weight, whichever is greater, but usually not on parcels under 1 kg.
DIM weight = L × W × H ÷ divisor; billable = max(actual, DIM, surcharge minimum)This page uses the same method as the Shipping DIM Weight Comparison Calculator, which explains each term and assumption in full.
| Service | Divisor | DIM weight | Billed at | Bills actual weight from |
|---|---|---|---|---|
| UPS Worldwide Express | 5,000 | 5 kg | 5 kg | 5 kg |
| FedEx International Priority | 5,000 | 5 kg | 5 kg | 5 kg |
| DHL Express Worldwide | 5,000 | 5 kg | 5 kg | 5 kg |
| Canada Post Xpresspost / Priority | 5,000 | 5 kg | 5 kg | 5 kg |
| Canada Post Regular Parcel | 6,000 | 4 kg | 4 kg | 4 kg |
| Australia Post Parcel Post | 4,000 | 6 kg | 6 kg | 6 kg |
Worked example
A 40 × 30 × 20 cm box weighing 3 kg, shipped via Australia Post Parcel Post.
- 1Sides as rated: 40 × 30 × 20 cm
- 2Volume: 24,000 cm³
- 3DIM weight: 24,000 ÷ 4,000 = 6.00, rounded up to 6 kg
- 4Actual weight: 3 kg
Billed at 6 kg (DIM weight).
Frequently asked questions
Why does Australia Post cubic weight seem so high?
Its factor, 250 kg per cubic metre, is the harshest of the major carriers: couriers use 200 (5000) and air cargo 167 (6000). A 40 × 30 × 20 cm box is 6 kg by cubic weight against 4.8 kg by DHL Express. Flat-rate satchels avoid cubic weight entirely.
What dimensional weight divisor does Australia Post Parcel Post use in 2026?
Australia Post Parcel Post divides cm³ by 4,000 and rounds up to the next 0.5 kg. It applies only from 1 kg actual weight.
Sources
- UPS, How to determine billable weight · checked
- FedEx, Dimensional weight · checked
- FedEx, 2026 surcharge and fee changes · checked
- USPS, Domestic Mail Manual: dimensional weight · checked
- DHL, How to calculate volumetric weight · checked
- Parcelforce Worldwide, How to measure a parcel for international delivery · checked
- Canada Post, How to cube an item and calculate its volumetric equivalent · checked
- Australia Post, What is cubic weight · checked
Related calculators
- DHL Volumetric Weight CalculatorDHL Express chargeable weight: centimetres divided by 5000, rounded up to the next half kilogram, compared with UPS, FedEx and the posts.
- Canada Post Volumetric Weight CalculatorCanada Post volumetric equivalent for Xpresspost and Priority (5000) and Regular Parcel (6000), next to the courier alternatives.
- Shipping DIM Weight Comparison CalculatorEnter a box once and see what UPS, FedEx, USPS, DHL, national posts and freight would each bill it as, side by side, and which penalizes it least.
- 30 × 20 × 10 cm Box Volumetric WeightChargeable weight for a 30 × 20 × 10 cm carton, small international orders and marketplace parcels, by express courier, national post and air cargo.
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