In short
- Revenue growth and margin growth are different outcomes; only a decomposition shows which force cancelled which.
- Volume, mix, price and input cost each move margin independently and can offset each other exactly.
- Mix is the effect most often missed, because it is invisible in a consolidated P&L.
- The worked example below is fictional and illustrative, and its four effects sum precisely to the margin movement.
The pattern
A business grows revenue, volume is up, the commercial team has had a good year — and gross margin in currency is flat or down. The management conversation then splits into positions rather than findings: sales blames input costs, operations blames discounting, and finance has a percentage that supports neither.
Price-volume-mix analysis resolves this by attributing the margin movement to the forces that caused it. It does not require new data; it requires the sales data at the level where price and quantity exist per product, and a consistent unit cost.
The four effects
- Volume — selling more or fewer units in total, holding the product mix and margins at prior-period levels.
- Mix — the same total volume distributed differently across products with different margins per unit.
- Price — the change in selling price on the units actually sold this period.
- Cost — the change in unit input cost on the units actually sold this period.
New and discontinued products are normally shown as their own effects, because attributing them to mix implies a comparison that never existed.
A small illustrative example
The figures below are entirely fictional and are used only to show the mechanics. They are not client data and do not represent any real business.
A company sells two products. Product A is a high-volume, low-margin line; Product B is a lower-volume, higher-margin line.
| Prior year A | Prior year B | Current year A | Current year B | |
|---|---|---|---|---|
| Units | 12,000 | 3,000 | 16,000 | 2,000 |
| Price per unit | $10.00 | $30.00 | $10.00 | $31.00 |
| Cost per unit | $6.00 | $20.00 | $6.50 | $20.00 |
| Margin per unit | $4.00 | $10.00 | $3.50 | $11.00 |
| Revenue | $120,000 | $90,000 | $160,000 | $62,000 |
| Margin | $48,000 | $30,000 | $56,000 | $22,000 |
Prior-year revenue is $210,000 and prior-year margin is $78,000. Current-year revenue is $222,000 — growth of $12,000 — and total units rose from 15,000 to 18,000. Current-year margin is $78,000. Revenue and volume both grew; margin did not move at all.
Decomposing the movement
Prior-year margin per unit across the portfolio is $78,000 ÷ 15,000 units = $5.20. Prior-year mix is 80% Product A and 20% Product B. Each effect is then calculated in turn.
| Effect | Calculation | Impact on margin |
|---|---|---|
| Volume | (18,000 − 15,000) units × $5.20 prior-year margin per unit | +$15,600 |
| Mix | A: (16,000 − 14,400) × $4.00 = +$6,400; B: (2,000 − 3,600) × $10.00 = −$16,000 | −$9,600 |
| Price | A: 16,000 × $0.00 = $0; B: 2,000 × $1.00 = +$2,000 | +$2,000 |
| Cost | A: 16,000 × −$0.50 = −$8,000; B: 2,000 × $0.00 = $0 | −$8,000 |
| Total | +15,600 − 9,600 + 2,000 − 8,000 | $0 |
The mix figures use the volumes the business would have sold at the prior-year mix: 80% of 18,000 units is 14,400 for Product A and 20% is 3,600 for Product B. Product A sold 1,600 units more than that, and Product B sold 1,600 units fewer.
Reading the result
The decomposition turns an unproductive argument into four specific findings. Selling 3,000 more units was genuinely worth $15,600. Shifting those units toward the lower-margin product cost $9,600 — a commercial and channel question, not a pricing one. The $1 price increase on Product B recovered $2,000. Input cost inflation on Product A took $8,000, and no price move offset it.
Three of those four are actionable next quarter: recover the Product A cost increase in price or specification, understand why Product B volume fell, and decide whether the mix shift is a deliberate strategy or an accident of where the sales effort went.
Getting it right in practice
- Run the decomposition at the level where price and quantity genuinely exist — SKU or product, not a revenue category.
- Use a consistent unit cost basis across both periods, and state whether it is standard or actual.
- Show new and discontinued products as separate effects rather than folding them into mix.
- Reconcile the sum of the effects to the reported margin movement exactly. If it does not reconcile, the analysis is not finished.
- Repeat it every month. A one-off PVM analysis explains history; a recurring one changes decisions.
Talk this through with Finviq
Tell us where your reporting stops short. In 30 minutes we'll identify the first two or three areas worth investigating in your business.