A firm’s fixed-cost spending, as opposed to its variable-cost spending, creates its operating risk, i.e., its exposure to an operating loss. This paper explores the quantitative dimensions of the operating risk and profitability of a firm’s fixed-cost spending. My findings are: (1) a firm’s ratio of total fixed cost [TFC] to its total contribution margin [TCM] represents the firm’s degree of operating loss exposure [DOLE] to uncertain economic swings, which is a direct measure of operating risk; and (2) the computed profit-to- risk gap [if zero or positive] can indicate the financial sustainability of the firm’s strategic fixed-cost spending initiatives. The DOLE and the profit return on TFC, [P/TFC] of financially sustainable firms are in their equilibrium at 61.8%. Fixed-cost spending decisions may use this equilibrium rate as the minimum required profitability on the relevant fixed costs and the maximum allowed risk. This paper demonstrates valuable applications of this risk-integrated framework in a sustainability analysis of two firms in the pharmaceutical industry.