By: Jennifer Brazer

Jennifer is the author of From Cubicle to Cloud and Founder/CEO of Complete Controller, a pioneering financial services firm that helps entrepreneurs break free of traditional constraints and scale their businesses to new heights.

Fact Checked By: Brittany McMillen

COGS & Inventory: A Powerful Partnership

COGS and inventory and how they work together represent a critical relationship at the heart of any product-based business’s financial health. When inventory items are sold, their cost value transfers from your balance sheet (as inventory assets) to your income statement (as Cost of Goods Sold), directly impacting your reported profits, tax obligations, and business valuation.

As the founder of Complete Controller, I’ve guided thousands of businesses through the complex dance between inventory management and COGS optimization. Over my 20+ years leading a cloud-based financial services provider, I’ve witnessed how mastering this relationship transforms struggling companies into profit powerhouses. In this comprehensive guide, you’ll discover practical strategies to align your inventory practices with COGS goals, proven methods to reduce carrying costs without sacrificing availability, and technology solutions that streamline the entire process. By implementing these approaches, you’ll gain tighter control over your product costs, clearer insights into your true profitability, and a competitive edge in your market.

How do COGS and inventory work together?

• COGS and inventory work together through a direct financial relationship where inventory becomes an expense (COGS) when sold
• Inventory represents an asset on your balance sheet until the moment of sale
• COGS directly impacts your gross profit margin, revealing your operational efficiency
• Inventory valuation methods like FIFO, LIFO, or weighted average determine how costs flow into COGS
• Efficient inventory management reduces carrying costs, shrinkage, and waste—all factors that inflate COGS

How COGS and Inventory Interact

The relationship between COGS and inventory forms the backbone of financial reporting for any product-based business. When you purchase inventory, it sits on your balance sheet as an asset. The moment you sell an item, its cost transfers from your asset column to your expense column as Cost of Goods Sold. This movement creates the direct link between inventory management decisions and your reported profitability.

This relationship between COGS and inventory affects everything from tax planning to cash flow. For example, holding excess inventory means tying up cash in assets that generate no return until sold. Meanwhile, these items incur storage costs, insurance, and risk of obsolescence—all expenses that eventually factor into your true COGS calculation, even if they’re not always tracked that way.

The financial relationship between inventory and COGS

Your choice of inventory valuation methods significantly impacts your reported COGS and therefore your taxable income. Each method creates different financial outcomes:

• FIFO (First-In, First-Out): Assumes oldest inventory sells first, reflecting current replacement costs in remaining inventory
• LIFO (Last-In, First-Out): Assumes newest inventory sells first, potentially lowering taxable income during inflation
• Weighted Average: Blends all inventory costs, simplifying calculations but potentially masking cost trends

A boutique with $260,000 COGS and $105,000 average inventory had a 2.48 inventory turnover ratio, meaning it sold all inventory every 147 days. This metric reveals how efficiently inventory converts to COGS—the higher the ratio, the leaner your operation.

Strategies for Optimizing COGS-and-Inventory Synergy

Strategic inventory management directly lowers your COGS by minimizing waste, reducing holding costs, and preventing stockouts that lead to expedited shipping expenses. Implementing these strategies creates a virtuous cycle where improved inventory practices continuously drive down your cost structure.

By analyzing sales patterns and seasonal variations, you can forecast demand more accurately, allowing you to maintain optimal inventory levels that balance availability against carrying costs. This approach prevents both overstocking (which increases storage expenses) and understocking (which risks lost sales and emergency shipping fees).

Proactive inventory management to reduce COGS

Walmart’s 2023 inventory turnover ratio was 8.2, nearly 3x higher than the boutique example, showing scale advantages in inventory management. Their advanced forecasting systems and vendor-managed inventory programs demonstrate how sophisticated approaches can dramatically reduce COGS at scale. For smaller businesses, similar principles apply with appropriately sized solutions:

1. Demand Forecasting: Use historical sales data, seasonal patterns, and market trends to predict future inventory needs
2. Economic Order Quantity (EOQ): Calculate optimal order sizes that minimize combined ordering and holding costs
3. ABC Analysis: Categorize inventory by value and turnover rate to focus management efforts on high-impact items
4. Supplier Relationship Management: Negotiate volume discounts, consignment arrangements, and just-in-time delivery terms

Case study: Reducing COGS through inventory optimization

Dell’s build-to-order model reduced inventory to under 1 day while generating $15M daily sales, proving JIT inventory slashes COGS. Their approach eliminated traditional warehousing costs by assembling computers only after orders were placed and paid for. This model transformed inventory from a cost center into a competitive advantage.

A manufacturing client of Complete Controller achieved similar results on a smaller scale by:

1. Implementing cycle counting instead of annual physical inventory
2. Establishing reorder points based on lead times rather than arbitrary levels
3. Negotiating vendor-managed inventory for high-volume components

These changes reduced their inventory holding by 34% while improving product availability, ultimately lowering their COGS by 12% and increasing gross margins significantly.

Common Pitfalls in COGS-and-Inventory Management

Many businesses underestimate the true cost of carrying inventory, tracking only the purchase price while ignoring substantial hidden expenses. Carrying costs of 20% ($10k/$50k inventory) for a motorcycle retailer show how excess stock directly inflates COGS. These costs include warehouse space, utilities, insurance, taxes, obsolescence, shrinkage, and the opportunity cost of capital tied up in inventory.

When calculating COGS, companies often miss critical components beyond the basic materials and direct labor. Complete costing must include:

• Inbound freight and customs duties
• Quality control and inspection costs
• Production supplies and packaging materials
• Warehouse labor for receiving and picking
• Allocated production overhead

Inaccurate inventory records and their impact on COGS

Discrepancies between physical inventory and accounting records create cascading errors in financial reporting. Common causes include:

• Unrecorded transfers between locations
• Theft and damage not properly documented
• Returns processed incorrectly
• Production scrap not accounted for
• Receiving errors and vendor shortages

These issues distort your COGS calculation, potentially leading to incorrect pricing decisions and tax reporting problems. Regular cycle counts and strong receiving procedures help maintain accuracy.

Misaligned tech systems

Many companies operate with disconnected systems for inventory management, order processing, and accounting. This fragmentation creates data silos where information isn’t shared effectively between departments. Symptoms include:

• Manual data entry between systems leading to transcription errors
• Timing differences causing temporary discrepancies
• Incomplete transaction records missing crucial cost details
• Inconsistent application of valuation methods
• Difficulty tracking actual costs per unit sold

Integrating these systems through modern ERP solutions eliminates these problems while providing real-time visibility into inventory levels and accurate COGS reporting.

Implementing Best Practices for COGS-and-Inventory

Successful businesses implement consistent procedures for tracking both inventory and COGS. Start by documenting your entire inventory management process from purchasing through sales fulfillment. Clearly define responsibilities for each step, establish control points to prevent errors, and create an audit trail for all transactions.

Develop standardized formulas for calculating carrying costs, reorder points, and safety stock levels. Review these calculations regularly to adapt to changing business conditions and market dynamics.

Inventory valuation & reporting

Choosing the right inventory valuation method requires understanding your specific business context:

• Products with short shelf life or rapid obsolescence typically benefit from FIFO
• Commodities with significant price volatility might use weighted average to smooth fluctuations
• Businesses in highly inflationary environments might prefer LIFO for tax advantages (where permitted)

Once selected, apply your chosen method consistently and document any changes in accounting policy. Regular reconciliation between physical counts and system records maintains accuracy in both inventory and COGS reporting.

Leveraging technology for improved COGS management

Modern inventory management systems automate much of the inventory tracking process, reducing human error while providing deeper analytical capabilities:

1. Barcode scanning and RFID: Capture accurate data at each inventory movement
2. Perpetual inventory systems: Track real-time levels without manual counting
3. Automated cost calculations: Apply consistent valuation methods to each transaction
4. Integrated accounting: Synchronize inventory and financial records automatically
5. Analytics dashboards: Visualize trends and identify opportunities for optimization

These technological solutions provide both operational efficiency and strategic insights into your inventory-COGS relationship.

Long-Term Financial Health Through COGS-Inventory Optimization

The ultimate goal of managing the COGS-inventory relationship is improving your overall financial performance. Average retail gross margins ranged from 15.01% (auto parts) to 71.52% (software) in 2023, proving COGS impacts vary widely by industry. Understanding where your business should fall within these ranges helps set appropriate targets.

By optimizing inventory for COGS reduction, you create a competitive advantage through either higher margins or more aggressive pricing. This optimization becomes a continuous improvement process, not a one-time project.

COGS’s role in pricing strategy

Your COGS directly influences your pricing flexibility. Lower COGS allows you to either:

1. Maintain current prices and enjoy higher profit margins
2. Reduce prices to gain market share while maintaining acceptable margins
3. Invest in quality improvements that justify premium pricing
4. Offer strategic discounts during competitive situations

Understanding your fully-loaded cost of goods sold provides clarity when making these critical pricing decisions. Many businesses unknowingly price products below their true cost because they haven’t accurately calculated all components of COGS.

Tax implications & compliance

Different inventory valuation methods significantly impact your reported taxable income. Working with tax professionals to model various scenarios helps identify the optimal approach for your situation.

Key considerations include:

• Consistency requirements for tax reporting
• Book-to-tax differences and deferred tax impacts
• State and local tax treatment of inventory
• Documentation requirements for audits
• International considerations for global businesses

Properly structured inventory and COGS practices provide both tax efficiency and audit protection while maintaining full compliance with how to calculate COGS in accounting regulations.

Conclusion: Mastering the COGS-Inventory Relationship

Throughout my years at Complete Controller, I’ve seen firsthand how businesses transform their profitability by mastering the relationship between inventory and COGS. The companies that succeed don’t view these as static accounting entries but as dynamic levers they can adjust to optimize performance.

The strategies outlined in this article provide a roadmap for creating this optimization in your own business. Start by understanding your current inventory-COGS relationship, identify your biggest opportunities for improvement, and implement changes systematically while measuring results.

Remember that this journey requires ongoing attention—market conditions change, product mixes evolve, and new technologies emerge. By establishing sound practices and regularly reviewing performance, you’ll maintain your competitive edge through efficient inventory management and accurate COGS reporting.

Ready to take your inventory and COGS management to the next level? Contact the experts at Complete Controller for personalized guidance on optimizing these critical financial components for your specific business situation.

FAQ

How do you calculate COGS using inventory values?

Calculate COGS by adding beginning inventory to purchases, then subtracting ending inventory (COGS = Beginning Inventory + Purchases – Ending Inventory). This formula tracks the flow of inventory costs from your balance sheet to your income statement as products are sold.

What’s the difference between COGS and operating expenses?

COGS includes direct costs of producing goods (materials, labor, manufacturing overhead), while operating expenses cover indirect costs like marketing, rent, and administrative salaries. COGS directly ties to each unit sold, while operating expenses support overall business operations.

How does inventory turnover ratio relate to COGS?

Inventory turnover ratio (COGS ÷ Average Inventory) measures how quickly inventory converts to sales. Higher ratios indicate more efficient inventory management, reducing carrying costs and lowering effective COGS. Low turnover suggests potential excess inventory, increasing costs through storage, obsolescence, and capital tie-up.

Why might businesses choose LIFO inventory valuation?

Businesses choose LIFO primarily for tax advantages during inflationary periods, as it matches current higher costs against revenue, reducing taxable income. LIFO also better matches current replacement costs in COGS, providing a more conservative picture of profitability when prices are rising.

How can small businesses improve their inventory-COGS relationship?

Small businesses can improve this relationship by implementing cycle counting instead of annual counts, using cloud-based inventory software that integrates with accounting, analyzing sales data to identify slow-moving items, negotiating better supplier terms, and calculating the true carrying cost of inventory to inform purchasing decisions.

Sources

• AccountingCoach. “What is COGS?” www.accountingcoach.com/what-is-cogs/explanation
• BILL. (2024). “Inventory Turnover Ratio: What It Is, Formula, and How It Works.” www.bill.com/learning/inventory-turnover-ratio
• Career Principles. (2024). “Inventory Turnover Ratio: Definition, Formula and Examples.” www.careerprinciples.com/resources/inventory-turnover-ratio
• Complete Controller. (2024). Internal Case Study.
• Investopedia. (2024). “Cost of Goods Sold (COGS).” www.investopedia.com/terms/c/cogs.asp
• Irvine Bookkeeping. (2020). “Inventory vs Cost of Goods Sold.”
• NetSuite. (2024). “COGS and Inventory Counts.”
• SaasAnt. (2023). “COGS in Inventory Management.”
• SlideShare. (2017). “Inventory Management of Dell Direct Model.” www.slideshare.net/slideshow/inventory-management-of-dell-direct-model/75551846
• Toast. (2024). “How Much Do Retail Stores Make? (2025 Data).” pos.toasttab.com/blog/on-the-line/how-much-do-retail-stores-make
• Wikipedia. “First-in, First-out.” en.wikipedia.org/wiki/First-in,_first-out
• Zoho Inventory. (2024). “What is Inventory Carrying Cost?” www.zoho.com/inventory/academy/inventory-management/what-is-carrying-cost.html

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