Size & weight guidelines

The size and weight of your parcel or letter determines your postage costs.

Maximum parcel size and weight

 Destination Maximum  weight Maximum length  Maximum dimensions 
Domestic 22kg  105cm  0.25 cubic metres 
International  20kg 105cm 140cm girth 

How we assess parcel charges

Domestic parcels are charged according to actual weight or cubic weight, whichever is greater. 

International parcels are charged according to actual weight.

Please note: You do not need to cube Australia Post prepaid or flat rate satchels. 

Calculating cubic weight for domestic parcels Click to expand Click to collapse

Cubing is easy; just follow the 2 simple steps below:

1. Measure your parcel

The images below show you how to measure regular and irregular shaped parcels, and satchels.

How to cube a parcel

Handy tip: when measuring the length and width of your parcel, always use the maximum points.

2. Cube your parcel

The cubic weight is the parcel's volume in cubic metres, multiplied by 250. To work this out, use the formula below:

Height x length x width x 250 = cubic weight

For example: 0.5m X 0.3m X 0.4m
= 0.06m x 250
= 15kg cubic weight

If the actual weight of your parcel is 10kg but the cubic weight is 15kg, we'll charge you the cubic weight because it is greater. But if the parcel's actual weight is 16kg, we'll charge you the actual weight because it is greater than the cubic weight of 15kg.

Please note: You do not need to cube Australia Post prepaid or flat rate satchels.

Calculating girth for international parcels Click to expand Click to collapse

The formula for working out the girth of your overseas parcel is:

Width + height x 2 = girth

For example: 30cm + 20cm
= 50cm x 2
= 100cm girth

Maximum letter size and weight**

Destination  Size   Maximum weight  Maximum dimensions Maximum 
thickness
Domestic  Small envelope 250g  130 x 240mm 5mm
Large envelope 500g 260 x 360mm  20mm
International  Small envelope 50g 130 x 240mm  5mm
Large envelope 500g 260 x 360mm  20mm

Does your item qualify as a letter?

To be considered a letter, your item must:

  • weigh less than 500g
  • contain flexible items
  • have a rectangular shape
  • be no larger than a B4 envelope (260mm x 360mm x 20mm)
  • be no thicker than 20mm

Is your item bigger than this? We would classify this as a small or large parcel.

* Some domestic parcel services have specific size and weight restrictions. Please check the service for more details before lodging your article.

While Australia Post accepts articles of the specified size and weight for International posting, some countries may have their own restriction on parcel sizes. Customers should confirm with the foreign postal agency if concerned.

** Letters should not contain stiff objects such as bottle tops, pens, items enclosed in a hard case, and so on. High-speed letter sorting equipment could damage such objects, or the objects could damage other articles.

Different size & weight restrictions apply to seasonal greeting cards, valid for postage between 1 November and 31 December. View domestic letter prices and International Airmail for more information.

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