Your WooCommerce dashboard says you made $50,000 last month. But how much of that was profit?
WooCommerce tracks revenue, orders, and refunds. It does not track what your products cost you, what you spent on shipping, what payment processors took, or what discounts eroded from your margin. Without that data, your revenue number is meaningless as a measure of business health.
Here is how to build margin tracking into your WooCommerce store, product by product, so you know which items actually make you money.
Why WooCommerce doesn't track margins
WooCommerce is an order management system built on top of WordPress. It was designed to process transactions, not to function as a financial analytics platform. The data model stores prices, quantities, and tax — but has no native field for cost of goods sold (COGS).
This means that out of the box, WooCommerce cannot tell you:
- Gross margin per product — what you keep after subtracting product cost
- Net margin per order — what you keep after subtracting all costs
- Which products lose money — after accounting for shipping, discounts, and fees
- Whether a promotion was profitable — or just gave away margin
Every merchant running WooCommerce needs to solve this gap. The question is how.
Getting COGS data into WooCommerce
There are three common approaches to adding cost data to your WooCommerce products.
Option 1: Custom fields (free, manual)
WordPress lets you add custom fields to any post type, including products. You can add a _cost_price meta field to each product and update it manually.
This works for stores with a small catalog. It breaks down quickly when you have hundreds of SKUs, variable products with different costs per variation, or suppliers who change prices regularly.
Option 2: COGS plugins
Several plugins add a cost field to the WooCommerce product editor:
- Cost of Goods for WooCommerce (WPFactory) — adds a cost field per product and variation, calculates profit in order reports
- WooCommerce Cost of Goods (SkyVerge) — similar functionality with bulk import support
- Product Cost for WooCommerce — lightweight option for simple stores
These plugins solve the data entry problem but still require you to keep costs up to date manually. They also only calculate the most basic margin (revenue minus cost), ignoring shipping, fees, and discounts.
Option 3: ERP or accounting integration
If you use an ERP system like Odoo or accounting software like Xero, your cost data already exists somewhere. Integrations that sync purchase prices from your ERP to WooCommerce product meta fields automate the COGS data problem.
This is the most reliable approach for stores with more than a few hundred products, but it requires setup and ongoing maintenance of the integration.
Calculating true margin per product
Having COGS data is step one. True margin requires accounting for every cost that reduces what you keep from a sale.
The full margin formula
True Margin = Sale Price - COGS - Shipping Cost - Payment Processing Fee - Platform/Plugin Fees - Discount Amount
Let's break each one down.
COGS (Cost of Goods Sold): The amount you paid your supplier for the product. For variable products, this should be tracked per variation — a Large might cost more to produce than a Small.
Shipping cost: What you actually pay to ship the order. If you offer free shipping, this is a cost you absorb. WooCommerce stores the shipping method and customer-facing shipping charge, but not your actual carrier cost. You need to track this separately or estimate it based on shipping zones and weights.
Payment processing fees: Most payment gateways charge a percentage plus a fixed fee. Stripe charges 2.9% + $0.30 per transaction. PayPal is similar. On a $20 order, that is $0.88 — or 4.4% of revenue. On low-priced items, processing fees can eat a significant portion of your margin.
Platform and plugin fees: If you use paid plugins, hosting, or services that charge per-transaction fees, these reduce your effective margin. WooCommerce itself is free, but many merchants pay for premium themes, plugins, and managed hosting that scale with order volume.
Discount amount: WooCommerce tracks coupon usage, but the discount cost is often overlooked in margin calculations. A 20% coupon on a product with a 30% gross margin leaves you with a 10% margin before other costs. Factor in shipping, fees, and COGS, and that product may be losing money.
Example: a product that looks profitable but isn't
| Line item | Amount |
|---|---|
| Sale price | $45.00 |
| COGS | -$18.00 |
| Shipping (your cost) | -$7.50 |
| Payment processing (2.9% + $0.30) | -$1.61 |
| Coupon discount (15% off) | -$6.75 |
| True margin | $11.14 |
| True margin % | 24.8% |
Without the full calculation, this product looks like it has a 60% gross margin ($45 - $18 = $27). The real number is less than half that. And if the shipping cost goes up or you run a bigger discount, this product dips below 20%.
Identifying products that lose money
Once you can calculate true margin per product, the next step is finding products where the margin is negative or dangerously thin.
Sort by margin percentage, not revenue. Your best-selling product might have terrible margins. A product generating $10,000 in revenue at 5% true margin contributes $500 to your business. A product generating $2,000 at 40% margin contributes $800.
Flag products below your break-even threshold. Calculate the minimum margin percentage you need to cover your fixed costs (rent, salaries, software). Any product below that threshold is costing you money to sell, even if the per-unit margin is positive.
Watch for margin erosion over time. A product that was profitable six months ago may not be today. Supplier costs change, shipping rates increase, and discount-heavy promotions can shift the economics. Track margin trends per product, not just snapshots.
Check variable products individually. A t-shirt might be profitable in sizes S through L but lose money in XXL because the COGS is higher and it ships in a larger box. WooCommerce reports won't show you this. You need variation-level margin data.
Building margin reports in WooCommerce
If you're doing this manually, here is the process:
- Export your order data from WooCommerce (including line items, coupons, shipping, and payment method)
- Map COGS to each product from your cost data source
- Calculate payment fees based on your gateway's rate structure
- Estimate shipping costs per order based on weight, zone, and carrier rates
- Subtract all costs from revenue per line item
- Aggregate by product to see true margin per SKU
This is a spreadsheet exercise that takes hours and needs to be repeated regularly. Most merchants do it once, realize how much work it is, and stop — which means they're flying blind on profitability.
How Spark automates WooCommerce margin tracking
Spark connects to your WooCommerce store via the REST API — no plugin installation required. Once connected, it pulls your order history, product catalog, and sales data, then calculates margins by accounting for the costs that WooCommerce ignores.
Instead of building spreadsheets, you ask questions:
"Which products have the lowest margins after shipping and discounts?"
"Show me products where margin has declined over the last 3 months."
"What's my true profit margin by product category?"
Spark cross-references order data, discount usage, shipping costs, and product costs to give you margin visibility at the SKU level. It also flags products where margin is trending downward, so you can adjust pricing or discontinue items before they become a drag on your business.
The goal is simple: know which products make you money and which ones don't. WooCommerce gives you the raw data. The missing piece is the analysis layer that turns orders into profitability insights.
See your true margins per product
Spark connects to WooCommerce and calculates real profitability — no plugins, no spreadsheets.