The short answer
Compare what is left from the same basket after each offer. Free shipping costs you the shipping charge you stop collecting. Ten percent off costs more as the basket grows. Our calculator shows the difference using your numbers. It does not predict which deal shoppers will choose.
In this guide
Write down four numbers first
You need the price of the items, what those items cost you, the shipping cost you pay, and the shipping charge the shopper pays. Use one currency for all four.
Here is a sample order: $40 of candles, $16 in product costs, $6 to ship, and a $5 shipping charge. With no offer, $23 is left: $40 plus $5, minus $16 and $6. That is before payment fees, tax, overhead, and any costs you left out.
- 01No offer
Sample order leaves $23.
- 0210% off
The same order leaves $19.
- 03Free shipping
The same order leaves $18, before fees and tax.
Compare the same order three ways
Ten percent off the $40 basket takes away $4. That leaves $19 after the costs above. A $5 discount leaves $18. Free shipping means you collect no $5 shipping charge, so it also leaves $18.
The carrier still costs $6 in each case. Do not count that $6 twice when you compare free shipping with the original order. Use the free offer calculator to see each amount beside the others. It does the arithmetic from your inputs.
A bigger basket changes the choice
On a $100 basket, 10% off costs $10. Giving up a $5 shipping charge costs $5, if that charge would still apply. Free shipping costs less in this example.
But larger orders can cost more to ship. Heavy mugs and light earrings should not use the same guess. Try a small, usual, and large order. If your store already gives that shopper free shipping, another free shipping offer does not give them a new saving.
Make the rules clear before checkout
If the offer needs a $50 order, say so near the offer. Name any excluded places or items. A shopper should not have to reach the last step to learn the deal does not apply.
Shopify supports free shipping codes and automatic free shipping discounts. Automatic means the offer can apply when its rules are met. Read the settings for countries, spend limits, and rates so your promise matches the setup.
Check what happens with other offers
A welcome code and a cart offer may both reach the same shopper. Check your Shopify discount combination settings before you test. Some offers can work together when set up to do so.
Use a sample basket to check the total with one code, then with the other offer. If a welcome code fails, try our welcome discount checker for a short list of things to inspect. Do not promise a deal until its rules work as expected.
Use the offer where it fits
You can choose offers for myuser.ai’s automatic follow-up. Its AI uses store and shopper details to write, schedule, and send messages. You choose what to turn on. You do not build a separate flow for every cart.
Start with an offer whose cost you understand. Some emails only need to answer a product question. Try the free email reviewer to make that note clear. Check the app cost as well as the offer cost when deciding what your store can spend.
Sources & notes
Sources checked 2026-09-14. Product facts come from the links below; examples explain the steps. Read our research method and testing limits.
- Shopify free shipping discounts help.shopify.com
- Shopify discount combinations help.shopify.com
- myuser.ai automatic follow-up myuser.ai