Free Shipping vs Paid Shipping: Where Is the Break-Even Point?
Free shipping can improve conversion and increase basket size. It can also transfer a meaningful cost directly onto the merchant. The right question is not whether customers like it — but what commercial improvement is required to pay for it.
“Free” shipping changes who pays. It does not make delivery cost disappear.
Shipping sits in an unusual position in ecommerce. Customers can see it before checkout, compare it immediately and sometimes use it as a reason to abandon a purchase altogether.
That makes free shipping commercially powerful. Removing an $8 delivery charge can reduce friction, improve perceived value and encourage a customer to complete the order.
But once the merchant absorbs the carrier cost, the economics of every qualifying order change.
The decision therefore has two sides: how much contribution is sacrificed per order, and how much additional demand or basket value that sacrifice creates.
Start with the order before shipping changes.
Assume an $80 basket produces $32 of contribution before delivery. The actual carrier cost is $8.
The shipping policy changes the economics before it changes the customer response.
Before estimating conversion uplift, isolate what happens to the contribution of a single order.
Customer pays shipping
Merchant funds all shipping
Free shipping above a threshold
The $8 subsidy removes 25% of contribution from every unchanged order.
How many extra orders must free shipping create?
Without the subsidy, each order contributes $32. With free shipping, each order contributes $24.
The business therefore needs more orders to generate the same total contribution.
Divide the old contribution per order by the new contribution: $32 ÷ $24 = 1.333.
At the same basket economics, order volume must therefore increase by roughly 33.3% just to return to the original contribution level.
Free shipping must improve conversion enough to overcome weaker contribution per order.
Below the threshold, free shipping buys revenue at the expense of contribution.
Extra orders fail to replace the contribution sacrificed on every subsidized shipment.
More customers convert, but the additional order count only compensates for the weaker contribution per order.
The commercial improvement becomes large enough to create more total contribution than the previous shipping policy.
A free-shipping threshold can make the customer help fund delivery.
Instead of subsidizing every basket, the business can require additional product contribution before shipping becomes free.
Current basket
An $80 basket produces $32 of contribution before shipping.
Customer adds $20 to unlock free delivery
At the same 40% contribution rate, that extra $20 contributes another $8 before shipping.
Incremental contribution funds the carrier cost
The additional $8 of product contribution approximately offsets the $8 shipping subsidy.
The $100 threshold becomes economically meaningful
The business can offer free delivery without automatically sacrificing the original $32 contribution generated by the $80 basket.
Average shipping cost is rarely the whole story.
A single break-even model is useful, but real shipping economics vary by order, geography, product and customer behaviour.
An $8 domestic shipment and a $19 remote shipment should not be treated as economically identical simply because both qualify for the same free-shipping promise.
Bulky or heavy SKUs can absorb far more contribution than small, lightweight products. Product mix therefore changes shipping profitability.
Two $100 baskets can create radically different contribution if one contains high-margin products and the other is dominated by low-margin items.
Free outbound shipping becomes more expensive when returns are common, particularly if the merchant also absorbs reverse logistics.
A first order with lower immediate contribution may still be rational if it acquires customers who return profitably. That requires evidence, not assumption.
That behaviour may be higher conversion, larger baskets, stronger retention or some combination of the three. But each benefit needs to be large enough to fund the shipping subsidy economically.
The alternative is not automatically “charge everyone shipping.” Thresholds, partial subsidies, geographic rules and product-specific policies can produce better economics than one universal promise.
Do not choose a shipping policy from conversion data alone.
At unchanged basket economics, order volume therefore had to rise by 33.3% just to break even.
A threshold can change the equation: if the customer adds enough profitable merchandise to the basket, the incremental contribution can fund some or all of the delivery cost.
Shipping is a conversion lever — but its real impact belongs in the profit calculation.
MarginLab helps ecommerce operators investigate product economics, margin pressure and the costs that sit underneath store revenue.