Key Takeaways
- Product cost connects to sales: Revenue minus COGS produces gross profit.
- Inventory changes matter: Costs tied to unsold inventory generally remain in inventory rather than becoming COGS immediately.
- Periodic calculation is simple: Beginning inventory plus qualifying costs or purchases minus ending inventory equals COGS.
- Costing methods can change reported results: FIFO, weighted average, specific identification, and LIFO where permitted can produce different COGS when prices change.
What COGS Includes
Product-related costs move into COGS when the associated goods are sold. Retailers may include merchandise purchases and freight-in. Manufacturers can also include direct labor, raw materials, and production overhead that is properly allocated to inventory.
General selling and administrative costs are usually separate. Marketing, corporate office payroll, and unrelated administrative expenses do not become COGS simply because they help the business operate.
Basic COGS Formula
The formula works because beginning inventory and new qualifying costs represent goods available for sale. Ending inventory removes the cost of items that remain unsold.
Example: A retailer begins the year with $40,000 of inventory, adds $170,000 of qualifying purchases and freight-in, and ends with $50,000 of inventory.
Result: $40,000 + $170,000 – $50,000 = $160,000 of COGS.
If the retailer recorded $260,000 of revenue, gross profit before other operating expenses would be $100,000.
Periodic vs. Perpetual Inventory
Periodic systems determine inventory and COGS at intervals, often using a physical inventory count at period-end. Under this approach, the basic formula above is especially easy to see.
Perpetual systems update inventory records as purchases and sales occur. Each sale can trigger a corresponding COGS entry. Physical counts still matter because shrinkage, damage, errors, and theft can create differences between the records and actual inventory.
Inventory Cost Methods
Businesses must determine which costs are assigned to goods sold and which remain in ending inventory. When identical or similar units were acquired at different prices, the cost-flow method can materially affect that split.
| Method | Basic idea |
|---|---|
| Specific identification | Tracks the actual cost of individually identifiable items |
| FIFO | Treats the earliest costs as the first costs moved to COGS |
| Weighted average | Uses an average cost for similar units |
| LIFO | Treats the most recent costs as the first costs moved to COGS, where the method is permitted |
IFRS IAS 2 uses specific identification for certain noninterchangeable items and FIFO or weighted average for ordinarily interchangeable inventory. LIFO is not an IAS 2 cost formula. U.S. tax rules permit LIFO in qualifying situations, subject to detailed requirements.
Why COGS Matters
COGS moves gross profit directly when revenue is unchanged. A higher COGS reduces gross profit dollar for dollar when revenue is unchanged, while a lower COGS increases it.
Inventory mistakes can therefore flow through to profit. Overstating ending inventory generally understates COGS and overstates gross profit for that period. Understating ending inventory does the opposite.
Taxable business income is also affected because inventory costs flow into COGS under applicable tax rules. Federal tax rules address how businesses that make or buy goods for sale handle inventory and production costs.
COGS vs. Operating Expenses
Product costs assigned to sold goods belong in COGS, while operating expenses support the broader business. These expenses can include selling, administrative, and other period costs.
Separating the categories helps readers understand gross margin before the rest of the company’s expenses. It also makes cross-company comparisons more meaningful when businesses classify costs consistently.
After COGS and the remaining expenses are accounted for, the company eventually arrives at measures such as net income.
Frequently Asked Questions (FAQs)
Is COGS the same as expenses?
It is an expense category, but it is not the same as all business expenses. COGS specifically reflects costs assigned to goods sold.
Does labor go into COGS?
Direct production labor can be included for manufacturers. Administrative, selling, and other labor that is not part of producing inventory is generally treated separately.
Can a service business have COGS?
Some service businesses report a similar cost-of-revenue or cost-of-services measure, especially when direct labor or materials are closely tied to revenue. Pure service businesses may not use a traditional inventory-based COGS calculation.
Why can FIFO and LIFO produce different profit?
When purchase costs change over time, the methods assign different cost layers to COGS and ending inventory. That changes gross profit even though the physical units sold may be identical.