Shipping Margin Calculator

It should at least not be an unexamined loss. Aggressive shipping margins depress conversion — checkout studies consistently rank surprise shipping cost as the top abandonment reason — but a small margin of $1–2 that funds packaging and the occasional surcharge is defensible. The failure mode is not charging too much; it is never doing this math.

The average across your real order mix, not the cheapest zone-1 label: base postage plus fuel and residential surcharges, delivery-area fees, and ideally packaging materials, since the box exists only because of shipping. Pull last month’s total shipping and packaging spend and divide by orders shipped — that blended figure is the honest input.

Set shipping charged to what the customer pays — zero — and the calculator shows the full label cost as the per-order subsidy your product margin must absorb. That is not automatically bad; free shipping is a proven conversion lever. It just needs to be priced into the product, which is what the number here tells you.

At least yearly and after every carrier general rate increase — GRIs land each January at 5–7% on average, and surcharges change mid-year too. A shipping charge set in 2024 against 2026 label costs is a slow leak. Re-run the math each January with the new rate card, and re-test your checkout charge if the margin went negative.