The Ultimate Guide to Raw Materials Inventory

What Is Raw Materials Inventory?

Raw materials inventory is the stock of basic inputs a company holds before production starts. It’s listed on the balance sheet as a current asset or materials the business plans to convert into finished goods within the year.

There are two types. Direct materials become part of the finished product and are defined by the Bill of Materials (BOM): fabric and thread for a clothing manufacturer, metal and wood for a furniture maker. Indirect materials support production without ending up in the final product, like lubricants, cleaning supplies, and packaging. Both need to be tracked, but they behave differently and require different approaches.

Managing raw materials means ordering, storing, and using these inputs while keeping accurate records tied to your BOM management. Without proper tracking, you either run out and stop production, or overbuy and tie up working capital in stock you can’t use yet. This usually works fine early on. Then order volume increases, SKUs multiply, and spreadsheets stop keeping up. What used to feel manageable turns into constant double-checking and last-minute surprises.

Raw Materials Inventory Formulas and Calculations

Raw materials inventory is the foundation of everything you make and the part of the supply chain most likely to quietly derail production. You can have the right demand forecast, the right production schedule, and the right customer order, and still lose it all because the materials aren’t there when the line needs them.

Getting raw materials management right means understanding what you have, when you’ll need more, and where the gaps in your tracking are creating risks you don’t know about yet. Two calculations are worth knowing well. They’re straightforward on paper, but only useful if the numbers feeding them are accurate.

Ending Raw Materials Inventory

This tells you the value of materials still on hand at the end of a period:

Example: A chemical manufacturer starts the month with $10,000 in materials for their chemical plant, purchases $5,000 more, and uses $8,000 in production. Ending inventory = $7,000. That figure carries forward as the beginning inventory for the next period.

Raw Materials Inventory Turnover Ratio

This measures how many times you cycle through your raw materials in a given period:

Example: A shoe manufacturer starts the quarter with $20,000 in rubber soles and ends with $40,000. Average inventory = $30,000. With $68,000 in COGS, the turnover ratio is 2.27, meaning they cycled through their raw materials just over twice that quarter.

Most manufacturers aim for a ratio between 4 and 6. Below 4 usually signals overstocking. Above 6 can mean you’re running lean enough to risk a stockout.

Raw Materials on the Balance Sheet

Raw materials are recorded at cost: purchase price plus shipping, handling, and storage. As materials enter production, their value moves from the raw materials account to work-in-process. When production finishes, it shifts to finished goods. When the product sells, that cost hits the income statement as cost of goods sold.

Of the three inventory types, raw materials are the least liquid. They need to be processed and sold before they generate cash, which makes accurate valuation important for understanding your real working capital position.

Raw Materials vs. WIP vs. Finished Goods Explained

Manufacturing inventory moves through three stages, and each one needs different handling.

Raw materials are inputs waiting to enter production: lumber, screws, flour, rubber. Work-in-process (WIP) is everything mid-production, assembled but not finished, mixed but not baked. Finished goods are complete products ready to ship.

From an operational standpoint, raw materials require supplier management and reorder planning. WIP needs production scheduling and quality control. Finished goods need demand forecasting and order fulfillment.

Collapsing all three into a single inventory number is one of the more common mistakes manufacturers make since it hides exactly where in the process problems stem from.

5 Areas Where Raw Materials Management Breaks Down

Most manufacturers think they have their raw materials under control. But, the data usually says otherwise. Here are the common problems that cause production disruptions:

1. Incorrect Counts

Your counts are wrong, and you don’t know it until it’s too late. Manual tracking with spreadsheets introduces errors every time someone forgets to log a transaction, updates the wrong cell, or works from a stale file. By the time you pull materials for a production run and find a shortage, you’ve already missed your window. The system said you had stock, but the floor disagrees.

2. Disconnected Systems

Purchasing and production are working off different numbers. When inventory data lives in disconnected systems, or worse, in personal spreadsheets, teams make decisions based on different versions of reality. Purchasing orders based on last week’s count. Production schedules based on what they were told last month. The result: you either run short mid-run, or you’re sitting on excess stock that ties up cash you could deploy elsewhere.

3. Ordering Too Late

You reorder too late because your data always lags. Without real-time visibility, reorder decisions are reactive. By the time low stock surfaces in a report, you’re already behind. Rush orders cost more. Expedited shipping eats into margins. And if a supplier is backordered, you’re stopping the line.

4. Inconsistent Suppliers

Supplier variability makes planning a guessing game. A supplier who usually delivers in two weeks but occasionally takes four, forces you to carry excess safety stock, just in case. That buffer has a cost. And when you’re managing multiple suppliers with inconsistent lead times, the math gets complicated fast. Forecasting demand accurately is hard enough before you layer in supply-side unpredictability.

5. Dead Stock 

Obsolete inventory accumulates silently. Materials ordered for a product that’s been redesigned, discontinued, or never launched don’t disappear from your warehouse. They sit there, taking up valuable warehouse space, showing up as assets on the balance sheet, and slowly becoming worthless. 

Without a system that flags slow-moving or unused stock, you won’t know how much of your inventory is actually usable. None of these problems show up all at once. They compound as the business grows, until managing materials turns into daily firefighting instead of a predictable system.

6 Steps for Controlling Raw Materials

The practices below aren’t new, but most manufacturers only partially implement them. Almost none of them work without accurate, real-time data underneath.

Step one: Set reorder points based on actual lead times and usage rates, not gut feel. When stock hits that level, a new order should be notified to you before the gap becomes a problem.

Step 2: Run cycle counts continuously instead of annual physical counts. Count a rotating portion of inventory every day or week. This catches discrepancies before they cause production issues.

Step 3: Maintain safety stock for critical materials, sized to your supplier’s realistic lead time variability and not the optimistic version.

Step 4: Diversify your supplier base for materials where a single-source failure would stop production. Having a backup supplier costs almost nothing until the day you need it.

Step 5: Standardize how materials are received, labeled, and stored. Inconsistent handling creates phantom inventory. Stock that exists in the system can’t be located or used.

Step 6: Track all three inventory stages separately. Aggregated inventory numbers hide where your actual problems are.

What You Can Do with Raw Materials Inventory Software

The operational complexity of raw materials management, which includes multiple suppliers, varying lead times, high SKU counts, and production schedules that shift constantly, quickly exceeds what spreadsheets and disconnected tools can handle reliably. The core issue isn’t effort. You’re not short on effort. You’re short on a system that keeps everything in sync. Spreadsheets and disconnected tools can’t keep purchasing, inventory, and production aligned as complexity increases.

Manual processes aren’t just slow; they create information gaps between the parts of the business that need to be in sync. When purchasing, inventory, production, and fulfillment are managed in separate systems, decisions in one area are routinely made on data that no longer reflects reality in another.

This is why manufacturers turn to inventory management software to take control of their raw materials. Real-time tracking means every team, whether in purchasing, production, warehouse, finance, works from the same numbers. When it’s time to reorder, the system alerts you and shows item-level gaps, including what’s missing to complete production. Cycle count discrepancies surface immediately. Instead of discovering a shortage when production is about to start, you know about it days in advance.

For manufacturers managing dozens or hundreds of SKUs across multiple locations, the gap between spreadsheet tracking and dedicated software is the difference between reactive firefighting and actually running a predictable operation.

If you’re looking for a tool to unify inventory, production, and purchasing while giving you real-time visibility into your raw materials, Digit uncovers inefficiencies in your raw materials management and lets you run a tighter operation. ​​When visibility into raw materials is working, you’re not guessing. Try Digit for free and know what you have, what you need, and what’s at risk before it impacts production.