How to Calculate Cost of Materials Used in Production

Accurately track your raw material consumption and manufacturing expenses.

What is Cost of Materials Used in Production?

The cost of materials used in production refers to the total value of raw materials and components that have been physically moved from inventory into the manufacturing process during a specific accounting period. This metric is a cornerstone of management accounting and financial reporting for any business that transforms inputs into finished goods.

For manufacturers, accurately identifying the cost of materials used in production is essential for calculating the Cost of Goods Manufactured (COGM) and, ultimately, the Cost of Goods Sold (COGS). Who should use this? Production managers, cost accountants, and business owners who need to monitor inventory efficiency, set product pricing, and maintain healthy profit margins.

Common misconceptions include confusing “materials purchased” with “materials used.” Just because you bought $10,000 worth of steel doesn’t mean you used all of it this month. If you only used $7,000, that is your actual cost of materials used in production, while the remaining $3,000 stays on your balance sheet as inventory.

Cost of Materials Used in Production Formula and Mathematical Explanation

To determine the cost of materials used in production, we use a logic-based accounting flow. We start with what we had, add what we bought, and subtract what is left.

The Core Formula:

Cost of Materials Used = Beginning Raw Materials + Net Purchases – Ending Raw Materials

Derivation Steps:

1. Calculate Net Purchases: This involves taking the gross purchase price, adding freight/shipping (Freight-In), and subtracting any returns or discounts.
2. Determine Total Materials Available: Add your Beginning Inventory to your Net Purchases. This represents the maximum amount you could have used.
3. Subtract Ending Inventory: Take a physical count or use a perpetual inventory system to find the value of materials still in the warehouse. The difference is what was consumed.

Variables in the Cost of Materials Used in Production Calculation

Variable	Meaning	Unit	Typical Range
Beginning Inventory	Stock value at the start of the period	Currency ($)	5% – 20% of annual sales
Net Purchases	Total new stock minus returns/discounts	Currency ($)	Varies by production volume
Ending Inventory	Unused stock at the end of the period	Currency ($)	Depends on lead times
Freight-In	Shipping and handling for materials	Currency ($)	2% – 10% of purchase price

Practical Examples (Real-World Use Cases)

Example 1: Small Furniture Boutique

A custom woodworker starts the month with $2,000 in timber (Beginning Inventory). They purchase $5,000 more wood, pay $300 for delivery, and receive a $100 discount for bulk buying. At the end of the month, they have $1,500 of timber left.

• Net Purchases: $5,000 + $300 – $100 = $5,200
• Available: $2,000 + $5,200 = $7,200
• Cost of Materials Used in Production: $7,200 – $1,500 = $5,700

Example 2: Industrial Electronics Assembly

An electronics firm has $50,000 in components. They order $200,000 in new parts with $5,000 shipping. They return $2,000 of defective sensors. Ending inventory is $40,000.

• Net Purchases: $200,000 + $5,000 – $2,000 = $203,000
• Available: $50,000 + $203,000 = $253,000
• Cost of Materials Used in Production: $253,000 – $40,000 = $213,000

How to Use This Cost of Materials Used in Production Calculator

Our tool simplifies the accounting process. Follow these steps for an accurate result:

1. Enter Beginning Inventory: Look at your balance sheet from the end of the previous period.
2. Input Raw Material Purchases: Sum all invoices for materials received during this period.
3. Include Shipping: Enter any Freight-In costs. Do not include Freight-Out (shipping to customers).
4. Deduct Returns: Enter the value of any materials sent back to suppliers.
5. Enter Ending Inventory: Input the value of materials currently in your warehouse.

The cost of materials used in production will update instantly, providing you with net purchases and consumption rates to help you decide if you are overstocking or under-utilizing resources.

Key Factors That Affect Cost of Materials Used in Production Results

• Supplier Pricing: Fluctuations in the global market for raw inputs like steel, plastic, or grain directly impact your base purchase cost.
• Inventory Shrinkage: Theft, damage, or spoilage reduces ending inventory and artificially inflates the cost of materials used in production.
• Freight and Logistics: Rising fuel surcharges increase Freight-In costs, raising the total value of materials available.
• Production Efficiency: High waste or “scrap” rates mean you are using more material to produce the same amount of goods, increasing the cost of materials used in production per unit.
• Volume Discounts: Purchasing in bulk reduces the unit cost, though it may increase storage costs and ending inventory levels.
• Tax and Accounting Methods: Whether you use FIFO (First-In, First-Out) or LIFO (Last-In, Last-Out) changes how you value your ending inventory and thus your final usage cost.

Frequently Asked Questions (FAQ)

1. Is labor included in the cost of materials used in production?

No. This specific calculation only focuses on direct raw materials. Labor is categorized separately as “Direct Labor.”

2. Does this include indirect materials like cleaning supplies?

Generally, no. Indirect materials are usually part of Manufacturing Overhead. The cost of materials used in production typically refers to direct materials that become part of the product.

3. What if my ending inventory is higher than my beginning inventory?

That is common if you are stockpiling. It simply means you purchased more than you used during that period.

4. Why is Freight-In included but not Freight-Out?

Freight-In is a cost necessary to get the material ready for use. Freight-Out is a selling expense related to finished goods delivery.

5. How often should I calculate this?

Most manufacturing businesses calculate the cost of materials used in production monthly to monitor gross margins.

6. What happens if I have a negative result?

A negative result usually indicates an error in inventory counting or data entry. Your ending inventory cannot physically be larger than what you started with plus what you bought.

7. Does inflation affect this calculation?

Yes. If material prices rise during the month, the cost of materials used in production will increase unless you have fixed-price contracts with suppliers.

8. Is this the same as Cost of Goods Sold (COGS)?

No. COGS includes labor and overhead for goods actually sold. The cost of materials used in production is just one component of the manufacturing cost.