How this calculation works
Fixed operating cost can make profit change faster than sales volume when unit contribution stays constant. Degree of operating leverage summarizes that local relationship at a stated base profit. This page calculates the complete changed-volume scenario as well as the base ratio. It therefore shows the currency change that a leverage percentage alone can obscure.
Contribution = units(price−variable cost); profit = contribution−fixed; DOL = contribution/base profitA worked example
One hundred units at price ten and variable cost six produce contribution four hundred. After fixed operating cost two hundred, base operating profit is two hundred and DOL is two. A ten-percent volume increase raises contribution to four hundred forty and profit to two hundred forty. The twenty-percent profit increase is twice the entered volume change under these linear assumptions.
Good to know
Capacity limits, discounts, staffing steps and changing unit costs are excluded. The arithmetic should not be extrapolated across a range where those assumptions stop holding. No production, pricing or debt recommendation is made. The result illustrates sensitivity around entered economics rather than guaranteeing the profitability of a growth plan.
Reference: OpenStax — single product profit sensitivity (opens in a new tab) ↗
What this calculation answers
Fixed operating cost can make profit change faster than sales volume when unit contribution stays constant. Degree of operating leverage summarizes that local relationship at a stated base profit.
This page calculates the complete changed-volume scenario as well as the base ratio. It therefore shows the currency change that a leverage percentage alone can obscure.
The Break-even calculator finds the zero-profit volume in a simpler scenario. Degree of operating leverage is undefined at that zero-profit base even though a new-volume profit can still be computed.
Use the right input conventions
Use one period and currency for all costs and revenue. Unit selling price, unit variable cost and total fixed operating cost are held unchanged between the base and comparison scenario.
The volume change is a percentage of base units, with the supported range kept above complete shutdown. The page does not predict that demand or operating capacity can actually accommodate the entered change.
Interpret the result
DOL is contribution divided by operating profit. It is undefined at zero base profit and can be negative when the base has a loss. The tool labels that condition instead of treating leverage as always a positive quality score.
Interest and tax are not included, so operating leverage here differs from financial leverage. Real step costs or price responses can invalidate the simple constant-cost volume relationship.
Work through the example
One hundred units at price ten and variable cost six produce contribution four hundred. After fixed operating cost two hundred, base operating profit is two hundred and DOL is two.
A ten-percent volume increase raises contribution to four hundred forty and profit to two hundred forty. The twenty-percent profit increase is twice the entered volume change under these linear assumptions.
Where the model stops
Capacity limits, discounts, staffing steps and changing unit costs are excluded. The arithmetic should not be extrapolated across a range where those assumptions stop holding.
No production, pricing or debt recommendation is made. The result illustrates sensitivity around entered economics rather than guaranteeing the profitability of a growth plan.
A few questions, answered
Why can DOL be undefined at break even?
It divides contribution by base operating profit, whose zero value makes a finite percentage sensitivity undefined.
What changes in the comparison?
Move the base to break even and inspect the undefined DOL alongside the still-defined profit scenario.