Operating Margin
Definition
Operating margin is operating income (revenue minus COGS and operating expenses) expressed as a percentage of revenue. It measures how efficiently a company turns revenue into profit from its core operations, excluding the effects of financing, taxes, and non-operating items.
Formula
Overview
Operating margin sits between gross margin and net margin on the profitability spectrum. It captures both the cost of delivering the product (COGS) and the cost of running the business (OpEx), but excludes interest, taxes, and one-time items. This makes it the best metric for evaluating operational efficiency.
For SaaS companies, operating margin improves with scale because many operating expenses (engineering, G&A) grow slower than revenue once the platform is built. This phenomenon, called operating leverage, is a key reason SaaS businesses can achieve high margins at scale despite being unprofitable during early growth phases.
Tracking operating margin by quarter reveals whether a startup is on a path to profitability. Investors at Series B and beyond expect a clear operating margin improvement trend. The Rule of 40 combines revenue growth rate and operating margin (or free cash flow margin) to assess the growth-profitability tradeoff.
Example
Revenue of $150K, COGS of $30K, and OpEx of $100K: operating margin = ($150K − $30K − $100K) ÷ $150K × 100 = 13.3 %.
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