How to Calculate True COGS for an Ecommerce Brand

When we audit a new client's books, the COGS number is wrong roughly 80% of the time — almost always too low. The founder thinks they have a 65% gross margin; the real number is 48%. Every downstream decision (CAC targets, pricing, ad budgets, hiring) is built on the wrong foundation.

What COGS actually means

COGS = every dollar you spend to turn a raw material into a unit sitting in your warehouse ready to ship. That's it. Not marketing, not warehouse rent, not your salary.

What belongs in COGS — the complete list

• Product unit cost from the manufacturer
• Component / raw material costs (if you assemble)
• Inbound freight (sea, air, rail) — proportionally allocated per SKU
• Import duties, tariffs, customs fees
• Inbound 3PL receiving fees
• Quality control inspections
• Labelling, packaging, branded inserts (when SKU-attributable)
• Pre-production samples (amortised across production runs)
• FX losses on supplier payments (the often-forgotten one)
• Manufacturing defects / shrinkage allowance

What does NOT belong in COGS

• Outbound shipping to customers → fulfilment / variable opex
• 3PL pick-and-pack fees → fulfilment
• Payment processing fees → variable opex
• Returns & refunds → contra-revenue (or its own line)
• Marketing & advertising — ever
• Warehouse rent — opex
• Salaries (including yours) — opex

Landed cost — the right way

Landed cost per unit = (unit cost + inbound freight + duties + inbound 3PL + QC + samples + FX) ÷ units in that PO

Recalculate landed cost per SKU per PO. Air-freighted units have a different landed cost than the same SKU shipped by sea. Averaging them hides one SKU bleeding margin.

Why mis-calculated COGS breaks decisions

• CAC target too high → you scale spend on customers who don't pay back.
• Pricing too low → you "win" on conversion and lose on the P&L.
• Wrong SKUs promoted → bestseller becomes the worst contributor.
• Misleading investor reporting → bridge gets uglier the closer they look.

Quick self-check

Add up the last 12 months of inbound freight, duties, QC and inbound 3PL fees. Divide by COGS in your books. If it's > 8% of COGS, you almost certainly have those costs sitting in opex instead of where they belong — and your gross margin is overstated by exactly that amount.

Fix order

• Pull the last 6 supplier invoices, freight bills, customs entries.
• Build a landed-cost worksheet per SKU per PO.
• Reconcile against your accounting system; reclass mis-coded entries.
• Reset your benchmark gross margin and update CAC / pricing targets.

We do this exercise inside the first 14 days of every fractional CFO engagement. It's unglamorous and it changes everything downstream.