Operating Leverage

Operating leverage comes entirely from a company's cost mix. Fixed costs — rent, salaried staff, depreciation, software infrastructure — don't move with sales volume. Variable costs — raw materials, hourly labor, shipping — scale directly with output. A company with mostly fixed costs (a software firm whose code is written once and sold infinitely) has high operating leverage: each incremental sale carries almost 100% gross margin. A company with mostly variable costs (a staffing agency that pays consultants per hour) has low operating leverage, because costs rise nearly in lockstep with revenue.

The Degree of Operating Leverage (DOL) quantifies the effect: it's the percentage change in EBIT divided by the percentage change in revenue. A DOL of 3 means every 1% change in revenue moves EBIT by 3% — in both directions. This is why high-operating-leverage businesses are described as 'high beta' operationally: their earnings are far more volatile through the cycle. DOL is mathematically highest just above the breakeven point (where EBIT is small) and falls as revenue climbs further above breakeven, because fixed costs become a smaller share of the total.

Interviewers love to test whether you can separate the two leverages. Operating leverage comes from the operating cost structure and magnifies how revenue changes flow into EBIT. Financial leverage comes from using debt in the capital structure and magnifies how EBIT changes flow into EPS (through fixed interest expense). A company can have high operating leverage and low financial leverage, or vice versa. Total leverage (combined) multiplies both effects — a software company financed with heavy debt would have explosive earnings sensitivity in both directions.