Calculated shipping for bulky parcels

[megadeckstaging]

Hi there,

I want to put calculated shipping for Australia and Worldwide in my seller listing, but it only allows me to select Australia Post Services, and only parcel size items. I want to sell a 2.4m x 0.6m stage with a depth of 18.8cm. How do I get calculated shipping for both Australia and overseas, using not just Australia Post services, on the listing tab?

Basically what we want is to choose a service that covers all countries, so when anyone from anywhere in the world looks at the listing, the posting calculates itself based on their location.