Aus Post calculator - to cube or not to cube?

[*wheels*]

I have a couple of boxes to post that are 800g. Once I pack them in an outer shipping box the postage calculator uses cubing and the postage price skyrockets. If I was to put the whole lot into an expandable tough bag is it still cubed?

[bnwt]

no

once it goes in a bag it is no longer a box

the TB6's can hold quite a lot

[*wheels*]

Great! Thanks, bnwt

[*wheels*]

I just ran down to the PO and bought a couple of the biggest expandable tough bags. They are size GL (maybe an old sizing?), maybe stands for "Good Lord woman, what do you need to post that needs a bag that size?"

Anyway, my carton just fits into it! Thanks again bnwt.

[golden]

Hi Wheels.  The young lady at the local post office (Kangaroo Flat) quoted $16 to send a package today.  Then she pushed in one corner of the box and said it's no longer cubed and charged $9.  I'm not sure what the rules are but it appears more expensive to cube.

[*wheels*]

Golden, the box I was sending would have cost $25.90 to send as a box, when I stuck the whole box into the tuff bag it cost $15.20 (plus the bag $1.85). Big Difference!

[*Brum6y*]

Cubing is a way of calculating a price for shipping an item based on the volume it takes up, rather than the actual weight.

It might sound weird, but if, for example, you were to send 50 bean bag refills, you could fill up a truck. If shipping were only charged on weight alone, then that full truck would have only had charges collected on (say) 50kg - if the bags were 1kg each.  When the truck might be capable of carrying 1 tonne, you can see that trip for the truck is going to be running at a big loss. Cubing addresses this problem.

They make it easier to work out a price by using a formula to calculate an equivalent weight (called the cubic weight) and then that is used to look up the normal weight tables.

Although in some parts of the world they use a different figure, the reference used by Australia Post (and a number of freight companies) for cubing is 250kg per cubic metre - which is equivalent to a 10 x 10 x 10 cm package weighing 250g. (³/₄ air and ¹/₄ water, for example)

While every parcel has a volume and, thus, can be cubed - the means of correctly doing this is only straightforward when the parcel is of a simple box shape: Length x Width x Height x 250Kg/m³. Add curves, irregular angles or indefinite edges (such as when shoved inside bags) and this simple formula is no longer usable.  Your Australia Post person who pushed the corner in made it non-rectangular and was able to charge you the normal weight based postage - because it could no longer be accurately assessed with the simple cubing formula they have in their computers.  While she did you a favour, I don't think the Australia Post hierarchy would be pleased.

Australia Post do not cube (or try to cube) everything - there are threshholds below which they just don't bother. For example, if the destination is within 50km of the sender. My truck example above isn't particularly relevant to short trips around suburbia - but when you start loading interstate trucks and especially planes, you can see it becomes much more of an issue.

If your parcel DOES come under the cubing rule, then they take the 'cubic weight' as described above and the actual weight, then use the greater of these two to look up their rate tables.

One thing to remember is that cubing will only cost you more in postage for parcels that are lighter than the reference figure ... anything heavier than that will be charged on actual weight - just like it has been for decades.

[*smee*]

to cube a non simple box shape is also simple .....you take the widest point of the 3 dimensions ie height , width and length using the same principal as if it was a normal box ..... this actually does form part of the Aust Post cubing rules along with every other kind of freight transportation in the world , its just that a lot of Aust Post staff cant get their head around it as they are not really transport minded people whom understand the logistics they are just counter staff

see here http://auspost.com.au/personal/parcel-dimensions.html

you will notice they even use a star shape as an example
however they only definatley will cube square or rectangular boxes
because its too hard to train the staff to understand the concept of cubing non standard shapes
they cover their staffs inability to understand how to cube by making this statement just in case someone does know how to do it

"Australia Post reserves the right to apply cubic charges to a parcel weighing less than 1kg and to parcels that are irregular or cylindrical in shape."

[*Brum6y*]

That link only refers to size limits on shapes - regular or irregular. It does not give guidelines on how the calculation for cubing is actually done - other than it is done for square or rectangular parcels.


But the last point is quite correct - even with the guidelines in place, Australia Post still 'reserve the right' to cube anything if they feel like it.

[*smee*]

yes you are correct , but the same principal applies , you measure the extremes

[*Brum6y*]

yes you are correct , but the same principal applies , you measure the extremes

..... there are so many directions one could take that statement

 - eBay
 - Paypal
 - Australia Post
 - discussing the colour of Uluru .....