Australia Post Cubic Weight Calculator
Calculate Australia Post cubic and chargeable weight from parcel dimensions using the published 250 kg/m³ factor.
Your results
Calculation breakdown
- Cubic weight
- length (m) × width (m) × height (m) × 250 kg/m³
Worked example
A 50 × 40 × 30 cm parcel occupies 0.06 m³ and has 15 kg cubic weight, so that exceeds its 10 kg actual mass.
Assumptions
- Dimensions are the maximum packed external measurements.
- The published 250 kg/m³ factor applies to the intended non-contract service.
Sources
Rates effective 23 August 2026.
How this calculator works
Calculate Australia Post cubic weight from maximum parcel dimensions and compare it with actual mass to identify the greater chargeable-weight basis. The comparison shows whether parcel space or physical mass is the larger figure before any service-specific pricing rules are applied. The result is kept transparent so the entered measurements can be checked against source records, physical labels and the operating plan before it is used.
Frequently asked questions
What should I verify for the australia post cubic weight result?
Measure maximum external points after final packing and confirm the current product rules, eligibility and quoted charge with Australia Post. Record the basis beside the result so another person can reproduce the estimate.
Why can the real australia post cubic weight outcome differ?
Flat-rate packaging, contract terms, rounding, service limits and Australia Post's own measured dimensions can change the billed result. Recalculate whenever a load, measurement, route or operating assumption changes.
Does this australia post cubic weight calculation prove compliance?
No. It is a planning calculation using the values entered. For this topic, measure maximum external points after final packing and confirm the current product rules, eligibility and quoted charge with Australia Post. Confirm current Australian requirements and competent advice wherever safety, legal compliance or equipment selection is involved.