Gross margin analysis: separate price, mix and cost
A gross margin bridge should explain the change in gross profit and margin using consistent revenue and cost definitions. Separate price, volume, product mix, input cost and accounting changes where evidence permits. Do not add percentage-point effects calculated on incompatible denominators.
Recalculate the reported margin first
Gross margin equals gross profit divided by revenue. Check whether freight, service, warranty and depreciation sit in cost of sales or elsewhere, and whether the classification changed. Two businesses can report different gross margins partly because they present costs differently.
IAS 2 describes inventory costs and recognition of inventory expense when related revenue is recognized. Inventory costing and write-downs can therefore matter when explaining a goods business’s reported gross profit. Read the company’s own cost policy rather than assuming every cost appears in the same line.
Hypothetical product-mix bridge
Assume two products have unchanged selling prices and unit costs. Product A generates a 50% margin and product B a 20% margin. Their revenue shares change while total revenue stays 100.
| Product | Prior revenue | Current revenue | Product margin |
|---|---|---|---|
| A | 40 | 60 | 50% |
| B | 60 | 40 | 20% |
| Total gross profit | 32 | 38 | Aggregate margin rises 32% → 38% |
The six-percentage-point improvement comes entirely from mix under these assumptions. It does not establish better pricing or lower unit costs. A management statement about “premiumization” is consistent with the arithmetic, but the actual product revenue split is required to test it.
Now suppose a four-unit inventory write-down also occurs in the current period and is included in cost of sales. Reported gross profit would be 34, not 38. Show the mix effect and write-down separately; do not quietly compare an adjusted current margin with an unadjusted prior margin.
Use an explicit bridge convention
When price and volume both change, their interaction requires a convention. You might apply prior-period prices to current volume first and then calculate price effects on current volume. Another order can allocate the interaction differently while reaching the same total. State the order so another researcher can reproduce it.
Create a source field for every bridge component. If management gives only a combined “price/mix” contribution, preserve that combined label. Splitting it into precise price and mix effects without data creates spurious detail.
Verify that segment changes reconcile to the group, including intercompany eliminations and unallocated costs. A newly acquired high-margin business can lift group margin without improving any existing product. Currency can also alter the revenue weights used in the aggregate calculation.
This bridge does not measure cash profitability and is less informative for businesses whose reported revenue is largely pass-through. A rising margin percentage can coexist with falling gross profit dollars. Keep both measures visible before concluding that economics improved.
A further check on the example
Run a dollar check beside the percentage-point bridge. If revenue falls from 100 to 70 while margin rises from 32% to 38%, gross profit falls from 32 to 26.6 despite the better percentage. Those additional hypothetical figures show why a margin story can conceal shrinking contribution. Before using the bridge in a thesis, state whether the mechanism aims to improve unit economics, total profit or both, and require the relevant measure rather than accepting any favorable margin statistic.
FAQ
Can higher margin be caused solely by mix?
Yes, as the example shows. That is why the product-level weights matter even when every product’s own margin is unchanged.
What if the company does not quantify drivers?
Present a qualitative bridge with verified directions and an unexplained residual. Do not invent exact percentage-point contributions to make a complete-looking chart.