Set the line above your current average order, at a level where the extra items people add cover the postage you'll absorb. Then make it visible in the cart. When we rebuilt Rick Grant's Gluten Free store with an A$135 free-shipping line and a cart meter as part of our conversion work, customers built baskets to within 20 cents of it.
It's one of the first things we look at, because postage decides whether small orders can ever pay for ads. Here's how to set yours, with the maths shown.
Why does a free-shipping line matter so much in Australia?
Postage here is dear compared with small orders. Australia Post charges by weight and distance, and for a cheap, light product a single parcel can cost more than the thing inside it. On a one-item order, postage can swallow the margin whole.
A free-shipping line fixes that from the other side. Instead of every order paying its own postage, customers add items to reach the line and the bigger basket carries the cost.
It also changes behaviour. People will go out of their way to avoid paying for shipping, which is exactly what we saw on Rick's store.
What happened on Rick Grant's store
Rick Grant's Gluten Free is a long standing Australian gluten free brand. Its hero product is a scone mix under A$9, the kind of item postage used to eat alive. When we rebuilt the store in August, we set the free-shipping line at A$135, added a cart drawer with a meter showing how far away it was, and built bundles so one choice got a basket most of the way there.
From our accounts · Rick Grant's Gluten Free · 17 to 20 Aug 2026
A$80average order on an A$8.85 hero product
Store orders from the first four days on the rebuilt store, with no ads running. Customers built baskets right up to the line, some landing within 20 cents of it.
Case study result. Outcomes vary.
No ads were running in those four days, so this was existing customers meeting the new store for the first time. People who came in for a scone mix left with a box. The store's best day came two weeks after launch.
Case study result. Outcomes vary. Best day A$1,066.58 (30 Aug 2026), one day, not an average.
How do I work out my threshold?
You need three numbers from your own store. Pull the last 90 days of orders if you can.
- Your average order, and where orders cluster. The average hides a lot. If most orders sit in one narrow range and a few big ones drag the average up, set the line from the cluster.
- What postage actually costs you per order. Use the rates you really pay: Australia Post retail rates if you buy postage over the counter or on a basic account, your contract rates if you have them. Add packaging.
- Your margin on the items people would add. The extra in the basket has to earn enough to pay for the postage you're now covering.
Then run one check. Take the gap between your average order and the line, remove the GST, and multiply by your margin. The answer should be at least what postage costs you. If it isn't, the line is too low to pay for itself, or your postage needs fixing first.
Worked example · made-up numbers
Say your average order is A$60, your products carry a 50% margin after product cost, and postage costs you A$11 an order.
A line at A$75 asks a customer to add A$15. Ex GST that's A$13.64, and half of it is A$6.82. That doesn't cover the postage.
A line at A$85 asks them to add A$25. That's A$22.73 ex GST, and half is A$11.36. That covers it, just.
The simple check leaves two things out. Orders already above the line now ship free too, so you lose any postage you used to charge them. And some people won't bother topping up, so a line set too high can cost you orders. Watch both for a month.
To see what free shipping does to your ad maths, put the postage you'd absorb into the break-even ROAS calculator and look at the return your ads would need.
How Australia Post's bands change the answer
Australia Post prices parcels by weight band and by how far they travel, so postage climbs in steps. Two things follow from that.
- Know where a basket at the line sits. If reaching the line pushes a typical order into a heavier band, the postage you absorb jumps too. Weigh a typical order at the line as well as your average one.
- Watch the far-away orders. A line that works for metro deliveries can lose money on remote ones. Some stores set a higher line for those areas, or keep a flat rate there.
Rates change, so re-run the sum whenever Australia Post changes its prices or you move to a new courier.
How do I get customers to aim for the line?
A line nobody sees does nothing. This is what we built into Rick's store.
- A meter in the cart that shows how much more gets free shipping, and updates as people add.
- Things that fit the gap. Cheaper items and multi-packs near the cart, so topping up is one tap.
- Bundles that get a basket most of the way in one choice.
- Per-serve pricing on small items, so adding one more doesn't feel like a big spend.
- The same line, in the same words, everywhere: the announcement bar, the product pages and the cart.
How do I know if the threshold is working?
Give it a month, then check four things.
- Average order value. It should rise.
- Orders just over the line. A cluster right above it means people are aiming for it.
- Conversion rate. If it drops, the line may be too high for a lot of your visitors.
- Postage as a share of sales. It should fall, even though you're paying for more of it.
If the order value rises and the conversion rate holds, keep it. If not, move the line and test again.
Questions about free shipping
Should my free-shipping line be above or below my average order?
Above it, usually. A line below your average order mostly gives free postage to people who'd have paid for it. A line a bit above it gives a lot of customers a reason to add one more thing.
Should I just offer free shipping on everything?
Only if your order value and margin can carry the postage on every order. For most stores selling lower-priced items, a threshold works better, because the bigger baskets pay for the postage.
What free-shipping threshold should an Australian store use?
There isn't one right number. Work it out from your own average order, postage costs and margin using the check in this guide, then test it for a month and watch the order value and conversion rate.
Sources
Rick Grant's Gluten Free: store orders from the first four days on the rebuilt store, 17 to 20 Aug 2026, with no ads running, and Shopify analytics for 30 Aug 2026. Postage: how Australia Post structures its parcel pricing, by weight band and distance. The worked example uses made-up numbers.
Jed Lynham, founder of Scaled Marketing. Published 24 Sep 2026. About Jed