COGS stands for cost of goods sold, the total cost a business spends to produce or purchase the products it sells during a specific period. It includes raw materials, direct labor, and manufacturing overhead tied directly to production. COGS is one of the most important numbers on an income statement because subtracting it from revenue gives you gross profit, the starting point for understanding whether a business is actually making money on what it sells.
What COGS Includes
COGS captures every cost directly tied to making or acquiring a product. For a manufacturer, that means raw materials (steel, fabric, wood, electronic components), wages paid to workers on the production line, and factory overhead like equipment depreciation and utilities for the manufacturing facility. For a retailer, COGS is simpler: it’s the wholesale price paid for the goods sitting on the shelves, plus shipping costs to get them there.
What COGS does not include is just as important. Rent for your corporate office, marketing campaigns, sales team salaries, and administrative costs all fall under operating expenses, not COGS. The dividing line is whether the cost is directly involved in producing or purchasing the product. A factory worker’s wages count. The HR manager’s salary does not.
The Basic Formula
The standard formula is straightforward:
COGS = Beginning Inventory + Purchases During the Period − Ending Inventory
Beginning inventory is everything you had in stock at the start of the period that wasn’t sold previously. You add any new inventory you produced or purchased during that time. Then you subtract whatever inventory is still on hand at the end of the period. What’s left is the cost of the goods you actually sold.
Say a furniture company starts the year with $50,000 in inventory, buys another $200,000 worth of materials and finished goods throughout the year, and ends the year with $60,000 still unsold. Its COGS for the year would be $190,000. That $190,000 is what the company spent to deliver everything customers bought.
Why COGS Matters
COGS directly determines gross profit, which is revenue minus COGS. If a company brings in $500,000 in sales and its COGS is $300,000, gross profit is $200,000. The gross profit margin in that case is 40%, meaning the company keeps 40 cents of every sales dollar before paying for rent, marketing, salaries, and other operating costs.
Tracking COGS over time reveals whether production is getting more efficient or more expensive. A rising COGS relative to revenue signals trouble: maybe raw material prices are climbing, labor costs are increasing, or the company is discounting products without cutting production costs. Investors, lenders, and business owners all watch this number closely because it’s the clearest measure of how efficiently a company turns inputs into sellable products.
COGS also matters at tax time. The IRS treats cost of goods sold as a deduction from gross receipts, reducing taxable income. Businesses that report COGS on corporate or partnership tax returns attach Form 1125-A to document the calculation. Getting this number right isn’t optional; it directly affects how much tax you owe.
How Inventory Methods Change COGS
The same company selling the same products can report different COGS figures depending on which inventory valuation method it uses. Three methods dominate:
- FIFO (First In, First Out) assumes the oldest inventory gets sold first. When prices are rising, FIFO produces a lower COGS because you’re recording the cheaper, older costs as sold.
- LIFO (Last In, First Out) assumes the newest inventory gets sold first. With rising prices, LIFO produces a higher COGS because you’re recording the more expensive, recent costs.
- Weighted Average blends all inventory costs together and assigns an average cost per unit.
A concrete example shows the difference. Imagine a company buys 200 chairs at $10 each, then later buys 300 more at $20 each, for a total of 500 chairs costing $8,000. It sells 100 chairs during the period. Under FIFO, those 100 chairs are valued at the older $10 price, so COGS is $1,000. Under LIFO, they’re valued at the newer $20 price, making COGS $2,000. Under weighted average, each chair costs $16 ($8,000 divided by 500), so COGS is $1,600.
That’s a $1,000 swing between FIFO and LIFO on the exact same sales. The method a company chooses affects reported profit, tax liability, and the value of inventory on its balance sheet. Once a business picks a method, it generally needs to stick with it for consistency.
COGS for Service Businesses
Pure service businesses, like accounting firms, consulting agencies, and real estate brokerages, typically don’t have COGS at all. They don’t manufacture or carry physical inventory, so there’s nothing to run through the COGS formula. Instead, they track “cost of services” or “cost of revenue,” which can include direct labor, subcontractor fees, and supplies used to deliver the service. These costs function similarly to COGS on a financial statement, but they don’t qualify for the same COGS deduction on a tax return because no physical product is being produced and sold.
Businesses that blend products and services, like a restaurant (food costs plus service) or a construction company (materials plus labor), do report COGS for the product-related portion. The key question is always whether a physical good changes hands.
COGS on Financial Statements
You’ll find COGS near the top of any company’s income statement, right below revenue. The layout typically looks like this:
- Revenue (total sales)
- − Cost of Goods Sold
- = Gross Profit
From gross profit, the company then subtracts operating expenses (marketing, rent, administrative salaries) to arrive at operating income, and eventually net income. Because COGS sits so high on the income statement, even small percentage changes ripple through every profit measure below it.
When comparing companies, COGS as a percentage of revenue is more useful than the raw dollar amount. A company with $10 million in revenue and $7 million in COGS (70%) is spending a much larger share on production than one with $10 million in revenue and $4 million in COGS (40%). Industry norms vary widely: grocery stores often run COGS above 70% of revenue because margins on food are thin, while software companies may have COGS below 20% since the cost of delivering a digital product is minimal after development.