Operating Margin

Operating margin measures profitability after both direct costs and overhead — selling, general, and administrative expense — but before interest and taxes. It answers whether the whole operating machine, not just the product economics, makes money. A company can hold a healthy gross margin and still post a thin or negative operating margin because overhead grew faster than revenue, which is one of the most common failure patterns in mid-sized private companies.

The relationship between gross margin and operating margin reveals cost structure. A distributor at 20% gross and 4% operating margin spends 16 points of revenue on overhead; if revenue drops 15% in a downturn and overhead is mostly fixed, that 4% operating margin goes negative fast. Credit analysts call this operating leverage, and it is why thin-operating-margin customers in cyclical industries deserve tighter limits than their current-year numbers alone suggest.

For private companies, normalize before judging. Owner salaries and perks routinely run through operating expense at above- or below-market levels, and rent paid to a related-party landlord can be off-market in either direction. A 2% reported operating margin with $800K of excess owner compensation is really a 5% business; the reverse adjustment applies when owners underpay themselves to dress up the statement.