In short
Learning goal: by the end of this lesson you can show shipping costs before they surprise anyone, and choose a free-shipping threshold from your own margins instead of copying someone else's.
The cart is where shoppers find out what the order will really cost. On most small stores that's the first time they see shipping. Baymard's checkout research lists "extra costs too high (shipping, tax, fees)" as the most common reason for abandoning a purchase, at 40% of shoppers who weren't just browsing, and "couldn't see or calculate the total order cost up front" at 12% (page updated 22 September 2025). Both are problems you can fix before you test anything.
What to measure at this step
| Metric | Definition | Role |
|---|---|---|
| Revenue or profit per visitor | Revenue (or gross profit) ÷ all visitors | Primary goal: shipping changes move both orders and order size |
| Average order value | Revenue ÷ orders | Secondary: shows whether a threshold grew baskets |
| Checkout-start rate | Checkouts started ÷ carts | Diagnostic: shows whether the cart loses people |
| Threshold reach | Share of orders at or above the threshold | Diagnostic: shows whether the threshold is in reach |
| Checkout completion | Orders ÷ checkouts started | Guardrail: must not drop |
Free shipping almost always raises orders per visitor, because it removes a cost. That's why conversion rate alone can't judge it: the question is whether the extra orders pay for the shipping you now cover. Revenue or profit per visitor answers that. Our explainer on revenue per visitor vs conversion rate goes through it.
Common problems
Shipping appears for the first time in checkout. The shopper has filled in an address and then sees a cost they didn't plan for. Fix: state shipping cost, or your threshold, on product pages and in the cart.
A threshold nobody reaches. Free shipping over $100 on a store where most orders are $35 is a sign, not an offer. Few shoppers will add $65 to save $5.
A threshold everyone reaches. Free shipping over $20 on the same store costs you shipping on nearly every order, and grows nothing.
A progress bar that doesn't match checkout. The bar says "You've got free shipping" but checkout charges it, because a discount lowered the subtotal below the threshold. Shopify counts products toward a free-shipping minimum at their discounted price when the discounts combine, and product discounts apply before the order subtotal is calculated. The bar must use the same number checkout uses. A Benchmyrk shipping test counts differently: its minimum is the cart before discounts, and its bar counts the same way.
Choosing a threshold: break-even first
A free-shipping threshold is mostly arithmetic. Each order contributes its product margin, plus any shipping the shopper pays, minus what shipping costs you. A threshold changes the middle part. The question is how many more orders, or how much bigger orders, you'd need to cover it. That's the break-even sales change from pricing analysis (Nagle and Müller), applied to shipping.
A store's average order is $38 (products only), its gross margin is 60%, shipping costs it $6.50 an order, and it charges shoppers $4.95 on every order. It's considering free shipping over $45, which it expects about 30% of orders to reach.
- Today each order contributes $21.25 after product and shipping costs.
- With free shipping over $45 and nothing else changing, each order contributes $19.77.
- To break even it needs +7.5% more orders, or average orders +6.5% bigger.
- With no change in orders or order size, profit per visitor changes by −7.0%.
Now the owner enters what she hopes will happen: the threshold pulls more baskets over $45 (40% of orders ship free), orders rise 5% and order value rises 8%. Then profit per visitor would change by +4.2%.
Computed with the free-shipping threshold calculator's own code (calculateShipping). The store is illustrative, and the expected changes are guesses entered to show how the calculator works, not predictions.
The example's useful line is the break-even, not the hopeful one. "Do I believe free shipping over $45 will bring 7.5% more orders, or baskets 6.5% bigger?" is a question you can think about from what you know of your customers. The expected-change line depends entirely on your guesses.
How to pick between thresholds:
- Just above your average order: more shoppers reach it, so it costs more, but it's the one most likely to grow baskets.
- Well above it: cheap, but few shoppers bother.
- Average order plus a popular add-on's price: gives shoppers an obvious way to reach it.
The progress bar
A progress bar in the cart ("$7 away from free shipping") turns the threshold into a small goal. It only works if it's true:
- It counts the cart the same way the offer does: after discounts for a Shopify free-shipping discount that combines with other discounts, before discounts for a Benchmyrk shipping test.
- It disappears or changes when the shopper changes country, if your threshold differs by market.
- It suggests something sensible to add, ideally a product around the gap.
Test ideas, and why they'd work
| Idea | Mechanism |
|---|---|
| Shipping cost stated on the product page | Removes the surprise that stalls carts |
| A threshold just above average order | Gives most shoppers a reachable reason to add one more item |
| A progress bar in the cart | Makes the remaining gap concrete |
| A small add-on suggested in the cart | Gives an easy way to close the gap |
At small-store traffic, the first one is a fix, and the threshold is a decision from the calculator. A test of two thresholds needs a lot of traffic, because revenue and profit goals vary more from order to order than conversion rate does.
A 10-minute exercise on your own store
- Find four numbers: your average order (products only), gross margin, average shipping cost per order, and what you charge for shipping.
- Open the free-shipping threshold calculator and enter them.
- Try a threshold just above your average order, and one $20 higher. Note each break-even change in orders.
- Pick the threshold whose break-even you find believable.
- Open your best-selling product on your phone. Is shipping cost or the threshold visible before the cart? If not, add one line.
Do it in Benchmyrk
Before Black Friday, the same calculator walk-through is in part 6 of the small-store series: pick a free-shipping threshold with the calculator. The full method is in our guide to free-shipping threshold tests.
Check yourself
- Free shipping raised your conversion rate. Did it pay? Answer: not necessarily. You now pay shipping on more orders. Check revenue or profit per visitor, or the break-even from the calculator.
- Your cart's progress bar says the shopper has free shipping, but checkout charges it. What's the likely cause? Answer: a discount lowered the subtotal below the threshold. A Shopify free-shipping discount counts the discounted price, so the bar must too.
- Your average order is $38. Is free shipping over $100 a good threshold? Answer: probably not. Few shoppers will add more than $60 to reach it. Try a threshold just above your average order, or average order plus a popular add-on.