Does free shipping actually increase sales?

Most of the time, yes. And the reason is more about how shoppers feel than what they pay.

Surprise delivery costs are the single biggest thing that loses you a sale. The Baymard Institute, which has studied checkout behaviour for years, found that around 48% of shoppers abandon their cart because the extra costs — shipping, tax, fees — felt too high once they reached checkout. It’s the most common reason people walk away, ahead of everything else. Shopify’s own figures point the same way: a large share of shoppers say they simply won’t finish a purchase if delivery isn’t free.

There’s a quieter psychological pull underneath that, too. People tend to value the word free more highly than a discount of the same amount. “Free delivery over £50” usually feels better than “£5 off your order,” even when the maths works out identically. It’s not entirely rational, but it’s consistent — and it’s worth designing around rather than fighting.

So free shipping helps. The real question isn’t whether to offer it, but how — because giving it away on every single order is rarely the smart move.

Free shipping vs a free-shipping threshold

The version that works for most stores isn’t free shipping on everything. It’s free shipping over a set spend — a threshold.

The difference matters. Flat free shipping on every order protects you against abandonment, but you pay for it on small orders where the postage can wipe out your margin entirely. A threshold gives you the same reassurance at checkout and gives the shopper a reason to add a little more to their basket to qualify.

That nudge is where the value is. When someone’s at £43 and free delivery kicks in at £50, adding one more item to avoid paying postage feels like a win to them — even though they’ve just spent more with you. Done consistently across a store, that’s where the 15–30% lift in average order value tends to come from.

Where should you set the threshold?

There’s no universal number, but there is a reliable starting point: set your threshold around 20–40% above your current average order value (AOV).

The logic is simple. If your average order is £40 and you set free delivery at £45, almost everyone qualifies anyway, so you’ve just given away shipping for nothing. Set it at £90 and it feels out of reach, so nobody stretches for it. Somewhere in that 20–40% band is usually the sweet spot — close enough that people will add an item to reach it, far enough that it’s actually moving your numbers.

Then watch it. Your AOV will shift over time, and the threshold should be reviewed alongside it rather than set once and forgotten.

What if all your products are a similar price?

The threshold only works when there’s something smaller a shopper can add to nudge their basket over the line. Plenty of stores don’t have that — if you sell a tight range of products at similar price points, say a publisher with a fixed catalogue of books, there’s simply nothing cheap to bolt on, so a threshold does nothing useful. In that case the better move is to build the delivery cost into the product price, offer genuinely free shipping on everything, and then advertise it loudly — on product pages, in the header, at checkout, everywhere. You get the same psychological pull of the word free and you remove the surprise-cost trigger entirely, and because the cost is spread evenly across the catalogue your margin stays intact. The only thing to check is that the slightly higher price still sits comfortably against what people would pay elsewhere.

A worked example

Say your average order value is £40.

• Set the threshold at £50 (25% above AOV).
• Add a progress bar in the cart: “You’re £12 away from free delivery.”
• A good chunk of shoppers sitting around £38–£45 will add one more thing to cross the line.

If that pushes your average order from £40 to £48, you’ve gained £8 per order — and on most product ranges, that comfortably covers the delivery cost you’ve absorbed, with margin left over. The shipping isn’t really free; it’s funded by the bigger basket it encourages. That’s the whole trick.

Common mistakes to avoid

A few we see regularly:

• Free shipping with no threshold. The most common one. You take the abandonment benefit but give away margin on every small order, including the ones that would have converted anyway.
• Setting the threshold below your AOV. If most orders already clear the bar, it’s not changing behaviour — it’s just a cost.
• Hiding the offer until checkout. The threshold only nudges people if they know about it early. Surface it in the header, on product pages, and as a progress bar in the cart.
• Never revisiting it. AOV moves. A threshold that was perfect a year ago may be doing nothing now.

Get those right and free shipping stops being a cost you grudgingly absorb and starts being one of the more reliable levers you have for order value.