SellersCalc

Freight math

Shipping Cost per Unit Calculator

A freight invoice only becomes useful once it is divided into the units it moved.

Shipping cost per unit = total shipment cost ÷ units shipped. An $1,800 freight bill spread across 500 units adds $3.60 to every unit — $360 per 100 units. That per-unit figure is the number that belongs in your landed cost and pricing math; the invoice total tells you nothing until it is divided. Run it per shipment, because the same product can carry $1.20 of freight on a full ocean container and $9 on an air-freighted restock — a swing big enough to flip a product from profitable to not.

Shipping Cost per Unit Calculator — your numbers

Shipping cost per unit

$3.60

Cost per 100 units

$360.00

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

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Worked examples

LCL ocean shipment

Total shipment cost $1,800.00
Units in shipment 500
Shipping cost per unit $3.60
Cost per 100 units $360.00

$3.60 per unit — the number that belongs in landed cost, not the $1,800.

Small air-freight restock

Total shipment cost $240.00
Units in shipment 48
Shipping cost per unit $5.00
Cost per 100 units $500.00

Rush restocks cost $5.00 per unit — often more than the ocean rate per unit ×3.

Frequently asked questions

What should the total shipment cost include?

Every charge tied to moving that shipment: the freight itself, origin and destination handling, documentation fees, customs brokerage, and final delivery to your warehouse. Leave out duty — it scales with product value, not shipment size, so it is cleaner to track as its own line in landed cost.

My shipment mixes several products — how do I split the cost?

Allocate by the resource the freight actually consumed: volume for ocean (each SKU’s share of CBM) or chargeable weight for air. Splitting evenly per unit overcharges small items and subsidizes bulky ones — a pallet of pillows should carry far more of the bill than a carton of phone cases.

How much does order size change my shipping cost per unit?

Dramatically, because a large share of any freight bill is fixed. If $650 of an $1,800 bill is fixed charges, doubling the order from 500 to 1,000 units drops the per-unit cost from $3.60 to roughly $2.45. That curve is the quantitative case for larger, less frequent replenishment orders.

Should I use air or ocean numbers when pricing a product?

Price against your steady-state mode — usually ocean — but know your air number, because stockouts happen. A healthy pattern is pricing on the ocean per-unit cost while keeping enough margin that an occasional air restock at 3–5× the freight cost dents profit instead of erasing it.

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Part of the Shipping & Landed Cost collection.