What the degree of operating leverage tells you
The degree of operating leverage measures how hard operating income swings when sales move. The formula is contribution margin / operating income. A DOL of 3x means a 1% rise in sales lifts operating income by roughly 3% - and a 1% fall in sales cuts it by roughly 3%.
Fixed costs are what drive the number up. When most of your cost base is fixed, extra sales carry almost their whole contribution straight to the bottom line, but a downturn leaves the same fixed costs in place and losses build fast. Two businesses with identical sales and identical operating income can have very different DOL, and the one with heavier fixed costs is the more exposed.
The table applies the DOL shown above to sales moves of plus or minus 5%, 10% and 20%. DOL assumes fixed costs and the variable cost per unit stay put, so once you add staff or equipment and change the fixed base itself, run the numbers again.
Written as of September 2026. This is an operating-level measure that excludes non-operating income, interest and taxes. Use it for planning and discuss financing decisions with your accountant.
Frequently asked questions
Not by itself. While sales are growing, high leverage turns extra revenue into profit quickly; when sales fall, it does the same in reverse. If your revenue outlook is uncertain, shifting fixed costs into variable ones lowers the risk.
DOL divides by operating income, so a zero denominator is undefined. Close to break-even, DOL heads toward infinity, which is itself the message: tiny moves in sales produce enormous swings in profit.