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

Domestic parcels over 1kg are charged according to their actual weight or cubic weight equivalent, whichever is greater. For parcels up to 1kg, cubic weight is only calculated if the parcel is large in size or irregular or cylindrical in shape.

International parcels

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.

3 different parcel shapes: 1. Box (measure length by width by height); 2 Irregular shape (measure length by width by height, each by their longest point); 3. Satchel (measure length by width by height, each by their longest point).

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: Width = 30cm, Height = 20cm
= (30cm + 20cm) x 2
= 50cm x 2
= 100cm girth

Maximum letter size and weight**

Destination  Size   Maximum weight  Maximum dimensions Maximum 
Domestic  Small envelope 250g^  130 x 240mm 5mm^
Large envelope 500g 260 x 360mm  20mm
International  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 only (if being sent within Australia)  
  • 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 for more information.

^ Maximum weight and thickness differs for small Express Post envelopes. For more information, visit our Express Post letters page.

Pick up your parcels when it suits you

Register for a free Parcel Collect address today!

Find out more