If you use the Australia Post extension for WooCoomerce, you can automatically have your items ‘packed’ into boxes for shipping calculations. If you’ve ever had issues with getting shipping costs that are too high because each item is being calculated individually, you’ll know how useful this can be.

Say you set up two ‘boxes’ in WooCommerce, a Small box and a Large box. If someone ordered 2 small items that fitted into the Small box, the shipping costs would be calculated based on all items going into one Small box. But if someone else ordered 10 items, shipping costs are calculated based on one Large box.

Planning to Use Shipping Boxes

Before setting up the plugin, you need to prepare your box sizes. And to do that, you need to know roughly how the extension works and what is involved in the setup.

Here is how it works:

  • set up your products, with the weight and dimensions for each product correctly configured (set the length, height and width for each individual product)
  • set up your boxes
  • for each box, accurately record the Inner dimensions (the available space for products to fit into) and the Outer dimensions
  • for each box, you also need to record how much the box weighs, and the maximum weight the box can carry.

Once it has these dimensions, WooCommerce can calculate automatically how to fit the contents of the shopping cart into available box sizes.

Calculations for Australia Post shipping costs are carried out by box. The weight is based on the weight of all the contents plus the weight of the box, and the size is based on the Outer dimensions of the box.

If you are using bubble wrap for some products, then you may need to add a suitable allowance to the product dimensions, particularly if you will be packing multiple bubble wrapped items in one box.

How do you find box sizes?

Australia Post publish detailed information about standard box and satchel sizes and the maximum weights for them on their website. If you plan on using their packaging, this is a good place to start.

Note Australia Post don’t provide Inner dimensions, so you’ll have to calculate these yourself. To get accurate Inner dimensions, measure the width of the box walls and deduct twice this amount from each of the Outer dimensions. So if a box has 5mm cardboard walls:
Outer Width: 220mm
Inner Width: 220mm less (2 x 5mm = 10mm) = 210mm

Satchel Rates

If you want to take advantage of Australia Post satchel rates, make sure you configure your boxes with Outer dimensions that are slightly smaller than the actual Australia Post satchel dimensions.

Are shipping costs calculated by weight or size?

Except for flat rate satchels, Australia post calculates domestic shipping costs based on EITHER how much your parcel weighs, or how big your parcel is, and it uses whichever is the greater.

So how does the costing by size work? Australia Post uses the notion of ‘cubic weight’. Consider this, if you packed 1kg of lead into a very small box, it is logical to calculate shipping based on weight. But if you packed feathers into a large box, it would be more logical to caculate shipping costs based on how much space the parcel takes up (it needs to fit into a delivery truck, after all).

Note For international parcels, costs are always based on weight.

This is how Australia Post explain it:
“Domestic parcels are charged according to actual weight or cubic weight, whichever is greater. International parcels are charged according to actual weight.”

See Australia Post Maximum Size & Weight Guidelines for the gory details of cubic weight, if you feel the need.

Configuring the Extension

The detailed documentation for the WooCommerce Extension includes step by step instructions for configuration – just make sure you’ve got all your box dimensions ready.

Here is an example of how it looks:

Box Packing Setup For Australia Post

Ready to configure? Here is a link to the detailed documentation:

Need Help?

If you want someone to build you a WooCommerce website that uses the Australia Post shipping calculator (or other shipping approaches), we would be happy to do so – more details here: WooCommerce Website Design & Build