In e-commerce, setting a selling price without knowing the exact cost price of each product is like flying blind. Many merchants rely on the supplier purchase price to estimate their margin, but this approach ignores dozens of hidden costs that erode profitability: shipping fees, commissions, packaging, returns, storage. The result: products you think are profitable are not, and others you overlook deserve more attention.
This guide shows you how to calculate the real cost price of each product in your catalog, identify the items dragging down your margins, and implement concrete strategies to optimize your profitability product by product.
The components of a product cost price
A product's cost price goes far beyond what you pay your supplier. It includes every expense required to get that product into your customer's hands. Here is a detailed breakdown of all cost components to consider.
| Cost item | Description | Example (product at 30 EUR) | Typical impact |
|---|---|---|---|
| Purchase cost | Price paid to supplier or unit manufacturing cost | 12.00 EUR | 35 - 50% |
| Inbound shipping | Supplier delivery to warehouse, customs duties | 1.20 EUR | 3 - 6% |
| Packaging | Box, cushioning, label, protective material | 1.50 EUR | 3 - 7% |
| Customer shipping | Carrier fees (UPS, FedEx, DHL, local carriers) | 4.50 EUR | 10 - 18% |
| Payment commission | Stripe, PayPal or bank gateway (% + fixed fee) | 0.70 EUR | 2 - 3% |
| Marketplace commission | Amazon, eBay fees or CMS subscription | 2.50 EUR | 5 - 15% |
| Acquisition cost | Share of marketing budget attributable to this product | 3.00 EUR | 8 - 20% |
| Storage | Warehouse rent, picking fees, stock insurance | 0.60 EUR | 2 - 5% |
| Return costs | Return shipping, reconditioning, value loss | 1.00 EUR | 2 - 8% |
| Customer support | Support time, partial refunds | 0.50 EUR | 1 - 3% |
In this example, the purchase price is 12 EUR but the complete cost price reaches 27.50 EUR, leaving a net margin of only 2.50 EUR on a product sold at 30 EUR. Without this detailed calculation, you would have believed your margin was 18 EUR.
Common mistake
Do not confuse purchase price with cost price. The purchase price often represents only 35 to 50% of the real cost price. Ignoring hidden costs can make you believe a product is profitable when it actually loses money on every sale.
Direct and indirect costs
Direct costs are attributable to a specific product: purchase cost, specific packaging, order shipping fees. Indirect costs (rent, salaries, software subscriptions, global marketing budget) must be allocated across products sold using an allocation key: proportional to revenue, units sold, or logistics weight.
- Direct costs: purchase price, packaging, shipping, payment commission, marketplace commission
- Indirect costs: rent, salaries, tool subscriptions, global marketing budget, overhead
- Recommended allocation key: proportional to revenue per SKU for fair distribution
Step-by-step cost price calculation method
Follow this six-step method to calculate the precise cost price of each product in your catalog. The goal is to obtain a reliable unit cost that includes all actual expenses.
Record the unit purchase cost per SKU
For each product reference, note the purchase price excluding tax from your supplier. Include customs duties, import taxes and procurement fees if purchasing outside your region. Update this amount whenever supplier pricing changes.
Calculate inbound logistics cost per unit
Divide the total cost of each supplier delivery by the number of units received. A shipment of 800 pieces costing 1,600 EUR in transport gives an inbound logistics cost of 2 EUR per unit. Include customs clearance fees where applicable.
Evaluate packaging and preparation costs
Add up the cost of materials (box, cushioning, tape, labels) and the labor cost of preparation. If an operator prepares 25 parcels per hour at 13 EUR/h, the preparation cost is 0.52 EUR per parcel, added to the material cost.
Include shipping and payment fees
Record the average carrier rate per parcel and add the payment commission (1.4% + 0.25 EUR for Stripe in Europe, for example). Calculate these costs on a monthly basis then break them down per unit for each product.
Allocate indirect costs per product
List your monthly fixed costs (rent, salaries, tools, marketing). Divide by monthly revenue to get an indirect cost rate. Apply this rate to each product's selling price. Example: 4,000 EUR in fixed costs / 20,000 EUR revenue = 20% of selling price in indirect costs.
Calculate the total cost price per product
Add all items: purchase cost + inbound logistics + packaging + shipping + commissions + indirect costs. Compare to the selling price excluding tax to get the net unit margin. Repeat for every SKU in your catalog.
Automate the calculation
Rather than maintaining a spreadsheet manually, use a tool like Fullmetrix that automatically imports your sales data, calculates the cost price per product and updates your margins in real time.
Identifying profitable and unprofitable products
Once the cost price is calculated for each product, the next step is to rank your items by profitability. The goal is to identify which products truly generate profit and which cost you money on every sale.
ABC analysis applied to product margin
ABC analysis is a classification method that groups your products into three categories based on their contribution to total margin. Applied to cost price, it quickly shows where to focus your efforts.
- Category A (20% of products, 80% of margin): your star products. Protect their margins, increase their visibility and stock
- Category B (30% of products, 15% of margin): intermediate products. Look to reduce their cost price to move them into category A
- Category C (50% of products, 5% of margin): low-contribution products. Analyze whether their cost price can be reduced or if they should be removed from the catalog
For each category C product, ask three questions: can the cost price be reduced? Can the selling price be increased without impacting volumes? Does this product generate traffic or cross-sales that justify keeping it despite a low margin?
Signs of an unprofitable product
- Net margin below 5% after integrating all costs
- Return rate above 10% inflating the real cost price
- Disproportionate customer acquisition cost relative to selling price
- Slow stock rotation increasing storage costs per unit sold
- High customer support costs (frequent complaints, replacements, refunds)
Optimizing your product cost prices
Reducing a product's cost price by just a few percent can have a considerable impact on your overall profitability, especially for high-volume items. Here are the most effective levers, ranked by potential impact.
Negotiate purchase costs
Purchase cost is the biggest component of cost price. Consolidate orders to get volume discounts. Regularly compare suppliers. Negotiate free shipping above certain order thresholds. On a high-volume product, a 0.50 EUR reduction per unit can save thousands of euros annually.
Optimize the supply chain
- Compare carriers and negotiate rates based on actual volumes
- Reduce volumetric weight by adapting packaging size to the product
- Consolidate multi-product shipments to share shipping costs
- Consider a third-party logistics provider (3PL) if volumes justify outsourcing
- Reduce rotation time to lower storage costs per unit
Reduce return costs
Every return increases a product's cost price: return shipping, reconditioning, value loss, processing time. To reduce this cost, improve your product listings (photos, descriptions, size guides), provide responsive customer service that resolves issues before returns, and analyze return reasons by product to identify problematic items.
Adjust selling prices
Sometimes the solution is not to reduce the cost price but to increase the selling price. If your analysis shows a product is sold below its real cost price, a price increase is necessary. Test in 5 to 10% increments and measure the impact on sales volume. A product with strong perceived value often supports an increase without significant volume loss.
The multiplier effect
Reducing the cost price by 1 EUR on a product sold 500 times per month generates 6,000 EUR in annual savings. Apply this logic to your 10 best-selling products and the impact on your profitability becomes considerable.
Fullmetrix: automatic cost price per product
Calculating cost prices manually for each product is feasible for a small catalog, but becomes unmanageable once you exceed a few dozen items. Fullmetrix automates the entire process by connecting directly to your e-commerce store.
- Automatic cost price calculation per product integrating all cost components
- Instant identification of negative or insufficient margin products
- Cost price evolution tracking over time to detect drift
- Automatic ABC analysis: ranking products by contribution to overall margin
- Visual dashboards with net margin per product, per category and per sales channel
- Automatic alerts when a cost price exceeds a defined threshold
With Fullmetrix, you move from a static spreadsheet to dynamic tracking of each product's profitability. Data is updated automatically with every order, return or cost change, enabling decisions based on reliable, up-to-date figures.
Time savings
E-commerce merchants using Fullmetrix save an average of 8 hours per month in manual calculations and identify in a few clicks the products dragging down their profitability.
FAQ on product cost price calculation
What is the difference between cost price and cost of goods?
The terms are often used interchangeably. Cost price generally refers to the complete cost of a specific product (all charges included), while cost of goods can refer to the overall cost of an activity or process. In the e-commerce context, both terms cover the same reality: the total of all expenses incurred to get a product to your customer.
How often should you recalculate cost price?
Ideally, cost price should be recalculated every month. Supplier rates, logistics costs and marketing expenses change constantly. Monthly recalculation helps detect drift quickly and adjust selling prices before profitability deteriorates. With an automated tool like Fullmetrix, recalculation is continuous and requires no effort.
How to factor promotions into cost price?
Promotions reduce the selling price without changing the cost price. Before launching a promotion, calculate the net margin after discount for each product concerned. A product with a 15% net margin cannot support a 20% discount without becoming unprofitable. Include the average promotion rate in your annual profitability calculation per product.
Should you calculate cost price for each variant?
Yes, if variants have different costs. An XXL t-shirt may cost more to purchase and ship than an S. A product in a special color may have a higher manufacturing cost. Calculate cost price per variant whenever cost differences exceed 5% to identify profitable variants and those that are not.
