Gross margin percentage is gross profit divided by net revenue. Gross profit is net revenue minus cost of goods sold (COGS). The percentage shows how much revenue remains after those costs; it does not establish net profit or cash available to spend.
For a buyer, gross margin helps evaluate how purchase prices, acquisition costs and product mix affect the goods sold. Procurement influences those inputs alongside pricing, production, waste, sales mix and the accounting policy. It does not control the whole result.
Gross margin formula
Gross profit = net revenue − COGS
Gross margin percentage = gross profit / net revenue × 100
Use revenue and COGS for the same period and scope. Net revenue should reflect the applicable returns, allowances and discounts. A zero revenue denominator does not produce a meaningful margin percentage.
The term “gross margin” is sometimes used for gross profit dollars as well as the percentage. Label the unit explicitly when comparing reports.
A worked example
Assume a fictional retailer reports $100,000 net revenue and $60,000 COGS for the same period:
Gross profit = $100,000 − $60,000 = $40,000
Gross margin = $40,000 / $100,000 × 100 = 40%
The $60,000 is the cost assigned to goods sold, not simply every purchase paid for in the period. Goods bought but still in inventory may remain an asset under the applicable policy. Conversely, this period's sales may include goods bought earlier.
IAS 2's inventory summary explains the recognition of inventory carrying amounts as expense when the related goods are sold under IFRS. The business's accounting framework determines the actual treatment, including losses and write-downs.
Gross margin vs markup
Markup uses cost as its denominator. Margin uses selling revenue.
| Fictional unit example | Calculation | Result |
|---|---|---|
| Selling price | $30 | |
| Cost assigned to the sale | $20 | |
| Gross profit | $30 − $20 | $10 |
| Gross margin | $10 / $30 | 33.33% |
| Markup | $10 / $20 | 50% |
A 50% markup therefore does not mean a 50% margin. Under this simple unit model, the price needed for a target margin is cost divided by one minus the target margin expressed as a decimal. For $20 cost and a 40% target, that gives $33.33 before rounding and any changes in discounts or cost scope.
A target price is not evidence that customers will pay it. Review demand, competitive context and the costs the gross profit must cover.
Gross profit, contribution and net profit
Gross profit subtracts COGS under the chosen reporting policy. Contribution measures subtract a defined set of variable costs. Net profit reflects the wider income-statement result, including the applicable operating, financing, tax and other items. These measures can answer different questions.
Do not say that all labor or rent is always outside COGS. Production labor and relevant production overhead can be part of inventory cost, while selling and administrative expenses have different treatment. A restaurant's ingredient-only menu margin is not automatically the same as its company gross margin.
Gross profit also is not cash flow. Customers may not have paid, suppliers may still be owed, and inventory may have been purchased in another period.
How buying decisions affect margin
Supplier prices. A higher unit cost can reduce gross profit when affected units are sold, assuming selling price and other costs stay unchanged. If 1,000 units sold each cost $0.30 more, the modeled gross-profit reduction is $300. The timing and accounting treatment must match the transaction.
Acquisition charges. Freight or duties that belong in the relevant inventory cost should be reflected consistently. An item sold for $28 with $12 goods cost has a goods-only margin of 57.14%. If another $2.40 of eligible acquisition cost applies to that sold unit, the resulting margin is 48.57%, a difference of 8.57 percentage points. This fictional comparison is not an industry benchmark.
Substitutions and quantity changes. Compare equivalent packs, specifications and usable quantities before accepting a replacement. Preserve the supplier proposal and buyer decision. A change in expected recipe economics is useful to know before it becomes realized COGS.
Invoice and receipt exceptions. A missing case, supplier credit and unagreed price increase are different events. Investigate and record them appropriately; adding every receiving variance to COGS can misstate the result. Purchase price variance also needs an explicit standard-price baseline and is not synonymous with an invoice failing to match the PO.
Compare periods without hiding the cause
A total margin can change because of selling prices, discounts, product mix, unit costs or accounting corrections. Separate these drivers before attributing the result to a supplier or buyer.
Compare similar categories and consistent cost definitions. An unweighted average of SKU margin percentages does not generally equal company margin: calculate total gross profit divided by total net revenue. Avoid imposing a universal “good margin” percentage across unlike businesses.
For inventory investment, GMROI compares gross profit dollars with average inventory at cost. It adds a different perspective rather than replacing the margin calculation.
Review the purchasing evidence in LineNow
LineNow's procurement workflow keeps supplier orders, replies, reviewed changes, receipts and additional-cost context connected. A living purchase order helps explain a cost change while preserving the original order and subsequent decisions.
Bring a price change, partial delivery and freight allocation to a demonstration. Confirm which operational item-cost reports use those values and how finance receives them. A cost update in a purchasing record does not by itself prove an immediate COGS entry or a complete gross-margin dashboard.