Standards and Financial Statements

Cost of Goods Sold (COGS) vs Operating Expenses (OPEX): Correct classification rules

Comparison of Cost of Sales vs Expenses (illustration)
Skip to content
Financial Performance Analysis COS vs OPEX

Cost of Goods Sold (COGS) vs. Operating Expenses (OPEX): Correct Classification Rules

One of the common errors in preparing the Income Statement is mixing direct costs with administrative expenses. Why does it matter? Because Cost of Goods Sold (COGS) is the only factor used to calculate your Gross Profit Margin. If you bury direct production costs inside Operating Expenses (OPEX), your profit margin will look misleadingly healthy. In this article, we provide a definitive guide to classification rules: What is the logic of direct vs. indirect? How does each type affect your final profit? And how do you avoid classification “Data Pollution”?

Illustrative design showing the difference between product production costs and office running costs.
Correct classification is the difference between a “Fake Margin” and a “Real Margin.”
What will you gain from this guide?
  • A clear, simple definition: What is COGS? and What is OPEX?
  • The “Direct Relation” logic: How to test any cost before classifying it.
  • A practical comparison table summarizing the core differences.
  • Visual model (SVG) explaining the profit ladder from Revenue to Net Income.
  • Detailed components of COGS (Materials, Labor, Direct Overheads).
  • Detailed components of OPEX (Selling, General, and Administrative).
  • Impact of classification on Gross Profit Margin vs. Net Profit.
To build the hierarchy first: Also read Account Classification Guide to see where these folders live in your system.

1) Defining COGS and OPEX

  • COGS (Cost of Goods Sold): The direct costs incurred to manufacture or purchase the products the company sold. If you don’t produce/buy the product, these costs disappear.
  • OPEX (Operating Expenses): The indirect costs required to run the company as a whole, regardless of the volume of production (e.g., Office Rent, Marketing, Management salaries).

2) The Logic: “Direct vs. Indirect”

To classify any cost correctly, ask this test question:

The Acid Test: If I stop producing this specific product tomorrow, will this cost go away?
  • Yes: It is likely COGS.
  • No (the cost remains to run the office): It is OPEX.

3) Key Comparison Table

Feature Cost of Goods Sold (COGS) Operating Expenses (OPEX)
Relation to Product Direct & Physical Indirect & Administrative
Impact on Income Statement Reduces Gross Profit Reduces Operating/Net Profit
Variability Strictly Variable with Volume Often Fixed or Semi-Fixed
Examples Raw materials, Factory electricity, Direct labor HQ Rent, CEO salary, Ads, Legal fees

4) Visual Model: The Profit Ladder

The Classification Impact Ladder Total Revenue Minus: COGS Direct Product Costs Equals: Gross Profit Core Business Health Net Operating Profit
The location of the cost determines which “Profit Level” is affected first.

5) COGS: The Direct Production Costs

In a manufacturing environment, COGS includes:

  • Direct Materials: Every component physically inside the product.
  • Direct Labor: Wages of people working on the production line.
  • Factory Overheads: Electricity, water, and depreciation inside the factory only.

6) OPEX: The Cost of Existence

Operational expenses are usually categorized as:

Recommended for you

Budget vs Actual Variance Analysis - Excel File

Budget vs Actual Template: Compares budget to actual by cost center and line item, capturing varianc...

  • Selling & Marketing: Ads, sales commissions, showroom rent.
  • General & Administrative (G&A): HQ rent, Office supplies, CEO and Admin salaries.
  • R&D: Costs of developing new products (not yet in production).

7) Impact on Gross Profit Margin

The Gross Profit Margin (Revenue – COGS) / Revenue is the most important metric for investors.

Example: If you sell a shirt for $100 and it costs $40 to make (COGS), your margin is 60%. The remaining $60 must be enough to cover all OPEX and still leave a Net Profit. If you misclassify office rent as COGS, your margin will look lower (e.g., 40%), misleading management into thinking production is inefficient.

8) Common Classification Mistakes

  • Factory vs. HQ Rent: Factory rent is COGS; HQ rent is OPEX.
  • Inbound vs. Outbound Freight: Freight to get materials (Inbound) is COGS; Freight to deliver to customers (Outbound) is OPEX.
  • Productive vs. Admin Staff: Production manager is COGS; Human Resources manager is OPEX.

9) Frequently Asked Questions

Is depreciation COGS or OPEX?

It depends on the asset. Depreciation of production machinery is COGS. Depreciation of office laptops is OPEX.

Why does it matter for tax?

In some jurisdictions, the timing of tax deduction differs between inventory costs (COGS – deducted when sold) and expenses (OPEX – deducted when incurred).

10) Conclusion

The summary is simple: COGS is the cost of “Doing the Work,” while OPEX is the cost of “Being in Business.” By mastering these classification rules, you ensure your financial statements provide a clear roadmap for efficiency: Is our production too expensive? Or is our administration too heavy? The answer lies in the correct folder.

Your Next Step: Look at your Income Statement. Can you pick three costs and justify why they are in COGS vs. OPEX using the “Acid Test”?

© Digital Salla Articles — General educational reference. For professional financial statement preparation or auditing, consult a certified public accountant.