Down to which line of which statement
The arithmetic is not the hard part. Choosing what goes in the numerator and the denominator is: whether cost of revenue includes selling costs, whether the operating income on the page is before or after interest, whether inventory divides by sales or by cost. Get one of those wrong and the answer is quietly off, with nothing to signal it.
So every input carries a note saying where to take it from, and every page says what its measure cannot tell you — how EBITDA hides capital spending, how a CAGR erases what happened between its two endpoints.
A figure needs something to sit beside
An 18% operating margin is not high or low on its own. Of 50 listed companies covered from SEC EDGAR and OpenDART, 45 have a calculable operating margin. Your figure is placed in that sample. The median operating margin across the set is currently 11.6%, the lowest company is at -13.0% and the highest at 61.2%.
Ratios remove the currency unit, but industry, fiscal-calendar and account-definition differences remain. This distribution describes the collected sample, not an industry norm or an investment ranking. Currency amounts are not converted; check each issuer’s dates and source filing.