shipping charges: transparency beats free, threshold math

business · 2026-10-13 · 5 min

shipping is pricing wearing a logistics costume: charge wrong and you fund every order or abandon every cart. the research says unexpected costs are the top avoidable abandonment cause — transparency beats free. here's the math and the models.

the numbers that decide

cart abandonment averages ~70% (baymard, 50 studies) — mostly browsing, but of avoidable causes extra costs top the list (~40% of abandoners cite high extras; ~20% slow delivery). three-quarters of shoppers want costs upfront (older shopify survey, directionally stable). conclusion: surprise kills more than price. show costs and estimates before checkout, always.

the four models

free shipping (baked into prices): highest conversion, needs margin math per order — works where average margin comfortably covers postage. flat rate ($X always): simple, predictable, slight over/under per order. calculated (carrier rates live): fairest, complex, best for heavy/varied carts. free-over-threshold ($X+ ships free): lifts basket size toward the line — set from YOUR average order value + postage + margin, not from competitors' banners. no universal threshold exists; test yours.

the threshold math (worked)

average order $45, postage $6, margin 50%: free-over-$60 converts browsers into $60 baskets — extra $15 at ~50% margin ($7.50) funds the $6 postage with room. threshold below average order: free shipping with extra steps. threshold absurdly high: decoration. recheck quarterly — carriers raise rates; thresholds must follow. the cart around it: why do people abandon their carts. taking the money: how to take payments online.

FAQ

free returns too?

separate decision: free returns lift conversion, invite wardrobing. categories with fit risk (apparel, shoes) often must; others price it in or charge. state the policy on product pages — hidden returns cost sales: trust signals.

charge international shipping fully?

usually yes, shown early — international surprises abandon hardest. duties transparency (who pays customs) prevents the angry-email kind of surprise.