Product Profit Margin: How to Calculate Margin by SKU
Product gross margin shows the percentage of net sales left after the product's cost of goods sold.
Gross margin % = (Net sales − COGS) ÷ Net sales × 100
Calculate the measure for the same SKU, period, location, and unit basis. Mixing product-level revenue with category-level cost produces a misleading result.
Worked product-margin example
A retailer sells 120 units of one SKU at an average net price of $25. Net sales are $3,000. The cost assigned to the units sold is $1,800.
Gross profit = $3,000 − $1,800 = $1,200
Gross margin = $1,200 ÷ $3,000 × 100 = 40%
Margin is not markup
Margin divides profit by selling price. Markup divides profit by cost.
- Margin % = (price − cost) ÷ price × 100
- Markup % = (price − cost) ÷ cost × 100
If cost is $15 and price is $25, margin is 40%, while markup is 66.7%. Confusing the two can cause pricing errors.
Which costs belong in product COGS?
Use the costing policy approved for the business. Product analysis may include purchase cost and allocable inbound freight, duties, packaging, or production cost. Marketing, rent, labor, payment fees, and returns may be analyzed separately to estimate contribution margin.
Do not silently mix gross margin and contribution margin. Label the report with its included costs.
Account for discounts, returns, and waste
Use net sales after discounts and returns. Update cost for damaged, expired, or wasted stock through the correct inventory process. In restaurants, theoretical recipe cost and actual food cost should be compared separately.
Use margin with inventory productivity
A high-margin product can still be a weak inventory investment if it sells slowly. Combine margin with:
- inventory turnover
- sell-through rate
- GMROI
- weeks of supply
- markdown and stockout history
GMROI is especially useful because it compares gross margin dollars with average inventory cost.
Build a SKU profitability table
| Field | Purpose |
|---|---|
| Net units and sales | Demand and realized price |
| COGS | Cost assigned to units sold |
| Gross margin $ and % | Profit before operating costs |
| Average inventory | Capital tied up |
| Stockouts and markdowns | Availability and demand risk |
Frequently asked questions
What is a good product margin?
Margins vary by category, channel, service model, and cost structure. Compare with the product's target, prior periods, and the business economics rather than a universal benchmark.
Should freight be included?
Inbound freight may be part of landed cost depending on the accounting policy. Apply the same rule consistently and consult an accountant for financial reporting.
Why does margin change when price does not?
Supplier cost, freight, discounts, returns, shrinkage, waste, and the inventory costing method can all change realized margin.
Can high-margin products be overstocked?
Yes. Margin does not measure sales velocity or capital tied up. Review turnover, weeks of supply, and GMROI as well.
Next step
Use reliable sales, cost, and stock data from the same period, then explore Stash inventory management software for connected inventory operations.
Turn better inventory decisions into a better operating system
Stash connects inventory tracking, forecasting, purchasing, suppliers, and multi-location visibility so growing physical businesses can act on the numbers with less manual work.
