Setting a free shipping threshold: do the arithmetic first

Aug 27
3 min read

Updated: 3 days ago

Introduction

A free-shipping threshold is one of the few levers in online retail that reliably increases average order value. It is also one of the easiest ways to give away your margin without noticing.

The difference between the two outcomes is a calculation most sellers never do. The number is usually copied from a competitor or picked because it sounds tidy.

1. Setting a free shipping threshold starts with your order distribution

Before choosing a figure, look at what customers currently spend.

Plot your orders by value and find where they cluster. The useful threshold sits a modest distance above the typical order — close enough that adding one item reaches it, far enough that reaching it genuinely increases the order.

2. Set it above your average order value, not at it

A threshold at or below the average simply gives free delivery to orders you were already getting.

The point is to move behaviour. If most orders sit around a certain figure, the threshold needs to be meaningfully higher, so that a customer has a reason to add something rather than qualifying automatically.

3. Check the margin on the increment, not on the order

This is the calculation that decides whether the threshold works.

If a customer adds an item to qualify, does the margin on that additional item cover the delivery cost you have just absorbed? On low-margin products it frequently does not, and the threshold then converts profitable orders into unprofitable ones.

4. Watch what happens to the orders just below the line

The threshold has an unhelpful side effect that is easy to miss.

Some customers who would have ordered at a lower value now hesitate, feeling penalised. Monitor whether small orders fall away, because a threshold that lifts average order value while reducing order count may leave you worse off.

5. Tell the customer how close they are

Almost all the behavioural effect comes from this one piece of communication.

A message in the basket stating the amount remaining to qualify, ideally with a suggestion of what would reach it. Without that prompt most customers never notice the threshold exists and it changes nothing.

6. Suggest the item that closes the gap

The prompt works far better with a concrete option attached.

Show low-priced, high-margin items that would take the basket over the line: accessories, consumables, small add-ons. This is where the extra margin comes from, and it is what makes the whole mechanism profitable rather than merely popular.

7. Vary it by region if your carriage costs vary

A single national threshold is wrong wherever delivery costs differ materially.

Remote areas, offshore addresses and international destinations can cost several times a standard domestic delivery. A uniform threshold means those orders are subsidised by everybody else, and the loss is invisible in aggregate figures.

8. Reconsider it when carriage rates change

Carrier prices rise, frequently annually, and thresholds do not adjust themselves.

A figure set two years ago against lower rates may now be below the point of viability. Diarise a review whenever your carrier pricing changes, since this is one of the commonest sources of quiet margin erosion in online retail.

9. Measure contribution per order, before and after

Judge the threshold on the number that actually matters.

Average order value, order count, delivery cost as a share of revenue, and gross contribution per order across the whole period. A rise in average order value alone is not evidence of success — it is exactly what you would expect to see even in the version that loses money.

Conclusion

Treat the threshold as an arithmetic problem based on your own order distribution and margins, not as a number to be copied.

Set it meaningfully above your average order value, check that the margin on the incremental item covers the carriage, watch whether small orders disappear, tell customers how close they are, suggest high-margin items that close the gap, vary the threshold where delivery costs vary, review it whenever carrier rates change, and judge the whole thing on contribution per order rather than average order value.