operating expenses (opex)
Also called: opex, operating costs
The costs of running the company that aren't part of delivering a specific sale: salaries, marketing, office, tools.
Operating expenses (opex) are the costs of running the company that aren't tied to delivering a particular sale: salaries of the in-house team, marketing, office and tools, software subscriptions, legal and accounting. Larger companies split them into sales and marketing, research and development, and general and administrative costs.
On the P&L they come after gross profit: gross profit − operating expenses = EBITDA, and after depreciation, operating profit. Most of them are fixed within a month, but fixed doesn't mean untouchable: marketing, hiring and tools are decisions that can be revisited every month.
Two boundaries cause most of the confusion. Marketing is an operating expense even when it works like an investment in future customers: the P&L records the money where and when it was spent. And opex differs from capex: buying something that serves for years (equipment, a platform built in-house) is capital expenditure, which reaches the P&L only gradually through depreciation.
Example
Klasna's operating expenses for September–November 2026:
They take 3,350,000 ÷ 6,832,760 = 49.03% of revenue. Gross profit of 5,108,699 covers them and leaves 1,758,699 of EBITDA. Marketing was a choice made month by month: 340,000 in September, 280,000 in October and 260,000 in November. The P&L charges each month what was spent in it, whether the families it brought stay for a year or leave after one package.
Common mistakes
- Calling marketing an investment to keep it off the P&L. It is expensed when spent; judge its payback separately.
- Treating fixed opex as untouchable. Fixed is about volume, not about whether it can be changed next month.
- Mixing opex and capex. Equipment and in-house platforms are capex; their cost reaches the P&L through depreciation.
- Cutting opex that drives next quarter's revenue. Check what each line brings before trimming it.
Learn it in the course
- How to read a P&L, top to bottom · How to read a profit and loss statement: revenue, cost of revenue, gross profit, operating expenses, EBITDA and operating profit, and what the P&L doesn't tell you.
- Case: a board report for a new board member · A board report on the quarter: rebuild Klasna's autumn P&L from raw lines, separate what will repeat from what won't, and back the memo with numbers.