Cost of Goods Sold (COGS) for E-Commerce: What You Need to Know
Understanding and accurately tracking COGS is essential for knowing your real profit margins as an online seller.
What Counts as COGS for an Online Store
COGS includes the direct cost of the products you sell — purchase price from suppliers, inbound shipping/freight, and any direct production costs if you manufacture your own goods.
What COGS Does NOT Include
Marketing costs, platform fees, payment processing fees, and warehouse rent are operating expenses, not COGS — even though they're necessary costs of running an e-commerce business.
The Inventory Valuation Challenge
As you purchase inventory at different prices over time, you need a consistent method (FIFO is most common) to determine which cost applies when you sell a unit. Inconsistent methods lead to inaccurate margins.
Why This Matters for Pricing Decisions
If you don't know your true COGS per product, you can't accurately calculate your contribution margin — meaning you might be running ads on products that are actually losing money once all costs are considered.
Multi-Channel Complexity
Selling on Shopify, Amazon and Etsy simultaneously means tracking inventory drawn from a shared pool across channels. Without proper systems, it's easy to lose track of true per-unit costs and channel-specific profitability.
Landed Cost Considerations
For businesses importing products, "landed cost" includes the product price plus freight, customs duties and any other costs to get inventory into your warehouse. Using just the supplier invoice price (ignoring these additional costs) understates your true COGS and overstates your margins.
Handling Bundles and Kits
If you sell bundled products (a kit containing multiple individual SKUs), COGS needs to reflect the combined cost of all components — which requires either bundle-specific cost tracking or a system that can calculate it from component costs automatically.
The Connection to Cash Flow Planning
Because inventory purchases happen before sales (sometimes months before, for businesses with long supplier lead times), understanding your COGS and inventory turnover helps predict how much cash you'll need tied up in inventory at any given time — critical for planning your next purchase order.
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