Incremental Margins
A company's average margin tells you how profitable all its sales are. The incremental margin tells you how profitable the next sales are, which often matters more for the future.
Why this matters for beginners
Businesses with high fixed costs can turn modest sales growth into fast profit growth, and the reverse in downturns. Learning objectives: calculate incremental margins, link them to operating leverage, and judge whether high incremental margins can last.
Main explanation
Incremental margin = change in operating profit divided by change in revenue between two periods.
When most costs are fixed, extra sales need little extra cost, so incremental margins can be far above the average margin. This is operating leverage.
Software companies often show very high incremental margins: one more subscriber costs almost nothing to serve. Retailers usually show lower ones, because each extra sale needs extra stock, staff and space.
Airlines are a classic example of operating leverage. Planes, crews and airport slots are largely fixed, so filling a few more seats lifts profit sharply, and empty seats hurt just as fast.
Very high incremental margins rarely last forever. Companies eventually hire, invest or cut prices. Check several periods and whether management is holding back necessary spending.
Example using a real company
A software company such as Adobe can add revenue with little extra cost, while a retailer such as Home Depot needs extra inventory and staff for each extra sale.
- →Revenue rises from 1,000 to 1,200 and operating profit from 150 to 230. Incremental margin = 80 / 200 = 40%, against an average margin of about 19%.
- →Revenue falls from 1,000 to 900 and profit from 150 to 90. Decremental margin = 60 / 100 = 60%: fixed costs magnify the decline.
Common beginner mistakes
- ✕Assuming the current average margin applies to future sales growth.
- ✕Extrapolating one strong year of incremental margins indefinitely.
- ✕Forgetting that operating leverage also works in reverse when sales fall.
Key terms
- Incremental margin
- Change in operating profit divided by change in revenue.
- Operating leverage
- How strongly profit reacts to a change in sales because of fixed costs.
- Decremental margin
- The share of lost revenue that disappears from profit when sales fall.
Key takeaways
- 01Incremental margins show how profitable growth is.
- 02Fixed costs create operating leverage in both directions.
- 03Judge over several periods, not one year.
Check yourself
- 01Revenue rises by 200 and operating profit by 80. What is the incremental margin?
- 02Why can incremental margins exceed the average margin?
- 03Why do software companies often have high incremental margins?
- 04What happens to a high-fixed-cost company's profit when sales fall?
- 05Why should you be cautious about very high incremental margins?
Try the concept on a real company
Open a company in the Analyzer and compare how much operating profit grew relative to revenue over recent years.
Educational examples only. Not buy or sell recommendations.