Published June 17, 2026
COGS sounds simple — "what I paid for the product." But in ecommerce, the real Cost of Goods Sold includes materials, packaging, inbound shipping, duties, and freight allocation. Missing any of these silently inflates your profit numbers. Most sellers we see underestimate their true COGS by 5 to 15 percent, which means they're pricing, advertising, and making decisions against profit figures that don't exist.
The base product price — what you paid your supplier or manufacturer per unit. This is the only number most sellers include, and it's the easy one.
Poly mailers, boxes, tissue paper, stickers, inserts, thank-you cards, tape, and labels. Individually these feel trivial, but on a $20 product they can easily add 60 to 90 cents per unit.
What you paid to get inventory to your door or to your 3PL. If a $1,200 shipment brings 1,000 units, that's $1.20 per unit in inbound freight that belongs inside COGS — not in "operating expenses."
Frequently ignored, frequently material. With 2026 tariff schedules on goods from China and other regions, duties can add 5 to 25 percent or more to your landed cost. If you're not rolling duties into COGS, your margins are fiction.
The per-unit cost of pallet shipping for large orders — the LTL freight, ocean freight, or air express charges that move bulk inventory from supplier to warehouse. Allocate it by units received, not by order.
Stop guessing your real cost per unit.
Get the COGS Calculator — $19The trick is the denominator. Every cost that scales with a shipment — freight, duties, inbound shipping — gets divided by the number of units in that shipment. Costs that scale per order (like a single box) get added directly. Mixing these up is the most common COGS error.
Beyond the five components above, there are softer costs that arguably belong in your unit economics even if your accountant treats them differently:
Let's say you import a product at $20 wholesale, 1,000 units per shipment, with packaging and freight. Here's the real per-unit COGS most sellers never calculate.
| Wholesale cost | $20.00 |
| Packaging per unit | $0.85 |
| Inbound shipping | $1.20 |
| Customs duties (5%) | $1.00 |
| Freight allocation | $0.45 |
| Per-Unit COGS | $23.50 |
The seller who only counts the $20 wholesale cost believes their COGS is $20. The seller who counts everything knows it's $23.50. That $3.50 gap is 15 percent of revenue on a $28 sale — and it's the difference between a profitable business and an expensive hobby.
Here's the part that hurts. Say you think your COGS is $20, and you priced for a 30% gross margin:
Looks great on paper. But if your real COGS is $23.50, your actual margin at $28.57 is:
You designed for 30% margin and shipped at 17.8%. Add platform fees, payment processing, ads, and returns on top, and you may be selling at a loss. Underestimating COGS by $3.50 doesn't shrink your margin by $3.50 — it shrinks it by the entire percentage gap, because every other cost is calculated against a sale price that was wrong from the start.
Every pricing decision, every ad bid, every "is this product worth scaling?" question depends on one number: true per-unit COGS. Get it wrong and everything downstream is wrong.
The cleanest method is per-product COGS tracking in a spreadsheet:
This is the methodology Ecommerce Profit Tracker PRO is built around. Each SKU has its own COGS row, and the per-order profit sheet pulls from it automatically — so when freight or duties change, you update one cell and every past and future order recalculates.
If your COGS line is just "what I paid the supplier," you're pricing against a guess. Ecommerce Profit Tracker PRO ships with a per-SKU COGS sheet, landed cost calculator (with duties and freight allocation), and a per-order profit tracker that uses your true cost — all formula-driven, no macros, for a one-time $19. Works in Excel and Google Sheets.
One-time payment · 7 sheets · Excel & Google Sheets