Operating leverage: why profits swing more than sales

Operating leverage describes how sensitive a company's operating profit is to changes in sales. When a large share of a business's costs are fixed, meaning they do not shrink when sales fall, each extra dollar of revenue adds a lot to profit, and each lost dollar takes a lot away. That is why the profits of some companies seem to swing far more than their revenue.

Fixed costs versus variable costs

Costs fall broadly into two groups:

• Variable costs rise and fall with volume. Raw materials, sales commissions and shipping are typical examples.
• Fixed costs stay roughly the same over a range of volume. Rent, salaries of permanent staff, depreciation of plants and equipment, and much research spending behave this way in the short run.

A company with high fixed costs and low variable costs has high operating leverage. A company with mostly variable costs has low operating leverage. A software firm with an expensive engineering team but very low cost per additional customer is one example of a high fixed cost structure. A staffing firm that pays workers only when it has contracts is closer to the other end.

The formula

The degree of operating leverage (DOL) at a given level of sales is:

DOL = % change in operating profit / % change in sales

DOL = Contribution margin / Operating profit

Contribution margin = Sales - Variable costs

A DOL of 4 means that a 10% change in sales is expected to produce roughly a 40% change in operating profit, in the same direction. The second form of the formula lets you compute it from a single year's figures if you know, or can estimate, the variable costs.

Example (illustrative numbers)

A company has sales of $1,000, variable costs of $600 and fixed costs of $300.

Contribution margin = 1,000 - 600 = 400
Operating profit    = 400 - 300 = 100
DOL = 400 / 100 = 4.0

Now see what happens when sales move by 10% either way, with fixed costs unchanged:

A 10% move in sales produces a 40% move in profit. If sales fell by 25%, operating profit would reach zero (sales $750, variable costs $450, fixed costs $300). That sales level is the break-even point.

Now compare with a company that has the same sales and profit but a mostly variable cost structure, for example variable costs of $800 and fixed costs of $100. Its contribution margin is $200, and DOL is 2.0, so a 10% change in sales changes profit by only 20%.

Adding financial leverage

Operating leverage is only the first layer. Debt adds a second layer, because interest is also a fixed cost. The combined effect is called the degree of total leverage:

Degree of financial leverage = Operating profit / (Operating profit - Interest)
Degree of total leverage = DOL x DFL

If the company in the example paid $50 of interest, its financial leverage would be 100 / 50 = 2.0, and total leverage would be 4.0 x 2.0 = 8.0. A 10% change in sales would then change profit after interest by about 80%. With sales down 10%, operating profit of $60 minus interest of $50 leaves just $10, compared with $50 in the base case. High operating leverage combined with high debt is what makes some cyclical companies so vulnerable. See the interest coverage ratio and the debt-to-equity ratio.

How to read it

Operating leverage is neither good nor bad in itself. It is a multiplier:

• When sales are growing, high operating leverage means margins expand, as fixed costs are spread over more revenue. Operating profit grows faster than sales.
• When sales are shrinking, margins compress rapidly and profits can disappear.

So the same company can look brilliant in an upswing and troubled in a downswing. This is why investors in businesses with high fixed costs, such as airlines, hotels and semiconductor manufacturers with expensive factories, tend to see volatile earnings. Understanding how earnings behave through the cycle is covered in cyclical stocks and normalized earnings.

A rough way to see it in reported results is to compare the growth in operating profit with the growth in revenue over several periods. If operating profit consistently moves several times as much as revenue, operating leverage is high.

Common mistakes and limits

Assuming costs are permanently fixed. Fixed costs are fixed only within a range. Over a longer period management can cut staff, close plants or renegotiate leases. Costs may also rise in steps when a company needs a new facility.

Calculating from reported numbers. Income statements do not label costs as fixed or variable, so any estimate of DOL from public data is approximate. A common shortcut, comparing percentage changes in operating profit with percentage changes in sales over time, gives a historical measure that reflects many other factors as well, such as price changes and acquisitions.

Treating the DOL as constant. It is highest near break-even, where profit is small, and falls as profit grows. A DOL measured at one sales level does not apply at another.

Ignoring the other side. A high DOL is attractive only if sales are likely to keep growing or stay steady. It should be compared with how stable demand is. A stable business with high operating leverage is a different proposition from a cyclical one.

Overlooking the margin structure. A high gross margin with high operating expenses often signals high fixed costs. Looking at where the costs sit in the income statement helps.

Where to see it on StocksXray

Operating leverage is not shown as a single figure. You can study it in the income statements within the SEC filings linked from a stock page, by comparing how operating profit moved against revenue in past upswings and downswings. Profitability carries 25% of the X-Ray Score and growth 20%, and each metric is ranked as a percentile within the company's own sector, so firms are compared with others that have similar cost structures.

Key takeaways

• Operating leverage measures how much operating profit changes for a given change in sales; it comes from fixed costs.
• DOL equals contribution margin divided by operating profit, and is highest near break-even.
• It amplifies both gains and losses, and combining it with debt amplifies them further.
• Fixed costs are fixed only for a time, so treat estimates as approximate.
• Stability of demand determines whether high operating leverage is an advantage or a risk.