Parcel math

Shipping Margin Calculator

Shipping is a line item with its own P&L, and most stores have never checked whether it is profit or subsidy.

Shipping margin = shipping charged − actual label cost. Charge $7.95 at checkout and pay $6.20 for the label and you earn $1.75 per order, a 22% margin on the shipping line. Plenty of stores run it backwards without noticing: a flat $5.00 charge against an $8.40 average label subsidizes every order by $3.40, and at 800 orders a month that is $2,720 of quiet margin leakage that never shows in net profit line items. Label costs creeping up? Dimensional weight on oversized boxes is the usual culprit. Enter your charge and your true average label cost to see which side of the line you are on.

Shipping Margin Calculator — your numbers

Shipping margin per order

$1.75

Shipping margin

22.0%

Estimate only. Results reflect exactly the numbers you enter — verify against your own accounting before making pricing decisions.

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Worked examples

Healthy flat rate

Shipping charged to customer $7.95
Actual label cost $6.20
Shipping margin per order $1.75
Shipping margin 22.0%

$1.75 per order: shipping quietly contributes instead of leaking.

Underpriced flat rate

Shipping charged to customer $5.00
Actual label cost $8.40
Shipping margin per order -$3.40
Shipping margin -68.0%

A $3.40 subsidy per order: real money at any volume.

Frequently asked questions

Should shipping be a profit center at all?

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.

What belongs in my "actual label cost"?

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.

How does this work if I offer free shipping?

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.

Carrier rates went up again — how often should I re-check this?

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.

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Part of the Shipping & Landed Cost collection.