What free shipping costs, and what it has to bring in.
Enter your orders, average order value, margin, and shipping fees. The calculation gives the monthly cost of the threshold, the orders or basket value you need to gain to pay for it, and how long a test would take to check.
Prefilled with the demo store’s cart (Maison Lune, fictional). It doesn’t say what its customers pay for shipping, so the fee is set to its cost, €6.90; replace it with yours.
Cost of free shipping
€58,591 / month
That’s the shipping revenue you stop collecting on orders that reach the threshold. To pay for it, you need to gain either:
- More orders
- 1,026 a month+5.0% orders, each leaving €57.11 once shipping is paid
- Or a higher average order
- €4.53 per order+4.4% on the average order, at the same order count
Would an A/B test see +5.0% more orders? With 3,402 visitors a day and 20.0% conversion, it takes 16 days, including three checkpoints.
Why judge the threshold on marginThe demo store’s threshold.
41.0% of the 20,711 monthly orders reach the threshold: free shipping costs €58,591 a month. To pay for it, you need +5.0% more orders, or €4.53 more per order.
An A/B test able to detect that rise in orders takes 16 days at this traffic. That’s the demo’s test, judged on margin per visitor, as told in the article “Measuring margin.”
Four calculations, no hidden assumptions.
The cost.
Orders × share reaching the threshold × shipping fee: what you stop collecting.
The margin of a free-shipping order.
Average order value × margin rate − delivery cost.
What you need to gain.
The cost divided by that margin, in extra orders; or divided by orders × margin rate, in extra euros per order.
The test length.
The same calculation as the duration calculator, for a conversion rate, with three planned checkpoints.
What the threshold really changes is measured on margin per visitor: see the cart and shipping use case.
Frequently asked questions.
Should you offer free shipping above an order value?
Only if it brings in more than it costs. It costs the shipping fees you no longer collect on orders that already reach the threshold; it brings more orders and bigger baskets. The calculator tells you how many you need; an A/B test tells you whether you get them.
Why judge the threshold on margin rather than revenue?
Because a threshold almost always lifts revenue: customers add an item to reach it. But each free delivery is paid for out of margin, and the revenue lift may not cover it.
How do you choose the threshold amount?
Just above your most common order value, so the extra effort stays small. Then test two amounts against each other, judged on margin per visitor: it’s the only way to know which one pays off.
Is my data sent anywhere?
No. The calculation runs in your browser; nothing is sent or stored.
Plan this test
A test plan calculates the same duration from your store’s measured traffic, sets its checkpoints, and seals them before the first visitor.
- Open demo, no sign-up
- Free to start, no overage charges
- Database and compute in Amsterdam, with Scaleway