What Is Operating Income?
Operating income is profit from the core business: revenue minus the cost of goods sold and all operating expenses, before interest and tax. It strips out how a company is financed so the trading performance stands alone.
Operating expenses are the costs of running the enterprise rather than making the product: research and development, sales and marketing, general administration and depreciation of office assets. A company that grows revenue while holding operating expenses roughly flat shows operating leverage — each extra sales dollar falls through to operating profit at a high rate.
Because interest and tax are excluded, operating income is the fairest basis for comparing companies with different debt levels or tax situations, and for comparing one company across years in which its borrowing changed. The operating margin — operating income divided by revenue — is the corresponding efficiency score.
Not everything in operating income is recurring. Restructuring charges, impairment write-downs and litigation costs sometimes sit inside it, and honest analysis separates them out using the filing's notes. When you see an unusual swing in a company's operating income in our tables, the 10-K's management discussion is the place that explains it.
Putting it into practice
Operating income is also the numerator in return calculations that compare profit with the capital used to earn it. Divide it by total assets and you approximate how productively the whole asset base is being sweated, before financing distorts the picture. Two companies can post identical operating margins while one uses three times the assets of the other to do it — a difference invisible in the income statement alone and obvious the moment the balance sheet joins the analysis. That is the deeper lesson of this guide: operating income is most powerful in combination, never in isolation.
A worked example from a real filing
Abstract definitions stick better with a real number attached. Take Nvidia Corp (NVDA): in fiscal 2026 it reported revenue of $215.94 billion in its annual 10-K filing, as republished in the SEC EDGAR company facts dataset retrieved in October 2026. Open its company page and you can place that figure next to the same company's net income, operating cash flow, total assets and diluted earnings per share for the same year — the relationships between the measures, not any single one of them, are where understanding lives. Then compare it with peers in the rankings, where the same measures are lined up across the largest filers.
For the full set of plain-English explainers, return to the Learn index, and for exactly how this site selects and labels figures, read the methodology page.