Work in process (WIP) inventory is the value of partially finished goods that manufacturers track between raw materials and finished goods. It covers the materials, labor, and overhead already invested in items still moving through production.
Tracking WIP closely gives you insight into both progress and expenses, which you can use to optimize operations, prevent bottlenecks, and reduce costs. A work in process inventory calculator turns those three figures into a single, reportable value you can put on the books.
Keep reading to learn what WIP inventory is, how to calculate it, how it appears on the balance sheet, and the best practices for managing it.
Key takeaways
- Work in process inventory represents the value of goods that have left raw materials but are not yet finished and ready to sell.
- The work in process inventory formula is beginning WIP plus manufacturing costs minus cost of goods manufactured.
- Work in process inventory is a current asset on the balance sheet, measured under GAAP until goods are completed and sold.
- Managing work in process inventory improves production efficiency, customer service, cost control, and financial reporting accuracy.
What is work in process inventory?
WIP inventory captures the value of products that are currently being manufactured. These items have moved beyond the raw material stage and are being transformed into finished goods, but aren’t yet ready for sale. WIP inventory includes the materials and labor costs used in the production process.
The value of a WIP item grows as it moves down the line. Each workstation adds labor and overhead on top of the raw material cost, so a unit halfway through assembly is worth more than one that just started. Capturing that accumulated value is what makes WIP inventory harder to track than a simple parts count.
Monitoring WIP inventory helps you understand your production efficiency. Too many items in production can signal bottlenecks or inefficiencies. Too few can signal a slowdown that leads to costly order fulfillment delays.
Tracking WIP inventory also matters because it is one of four types of manufacturing inventory. It sits alongside raw materials, finished goods, and maintenance, repair, and operations (MRO) supplies, and it represents a portion of your reportable assets.
Work in process vs. work in progress: what’s the difference?
You might hear “work in process” and “work in progress” used interchangeably. Both terms refer to ongoing, unfinished projects. “Work in process” is usually preferred in manufacturing for goods produced over a short time. “Work in progress” is more common in construction. Note that Fishbowl Advanced uses the term “work in progress.”
How does the work in process inventory calculator work?
A work in process inventory calculator applies one formula to three inputs and returns the value of goods still in production. Gather the three metrics below, then plug them into the formula to get your ending WIP value.
1. Gather three key metrics
To calculate WIP inventory, you need your manufacturing costs, beginning and ending WIP inventory costs, and cost of goods manufactured (COGM).
- Manufacturing costs: how much it costs to manufacture finished goods, including raw materials, labor, and overhead.
- Beginning WIP inventory cost: the value of WIP at the start of the period, carried over from the previous period’s end.
- COGM: the total value of goods completed and moved out of WIP. It equals manufacturing costs plus beginning WIP inventory minus ending WIP inventory.
2. Use the work in process inventory formula
The core formula is:
Ending WIP inventory = Beginning WIP inventory + Manufacturing costs − COGM
Consider an office supplies maker that produces printers and copiers. Its beginning WIP is $8,000, manufacturing costs are $40,000, and COGM is $45,000. Run those numbers through the calculator and it returns an ending WIP of $3,000.
| Input | Value |
|---|---|
| Beginning WIP inventory | $8,000 |
| Manufacturing costs | $40,000 |
| Cost of goods manufactured (COGM) | $45,000 |
| Ending WIP inventory (result) | $3,000 |
How often you run the calculator depends on your operation. Manufacturers with long production cycles often calculate WIP monthly or quarterly to match their accounting periods. Job shops and custom producers may calculate it per job, so each order carries its own cost record. Running the numbers on a consistent schedule keeps your beginning and ending values aligned from one period to the next.
How is work in process inventory recorded on the balance sheet?
On the balance sheet, work in process inventory is a current asset reported under inventory. As items move through production, their costs shift from WIP to finished goods, and then to cost of goods sold (COGS) once the goods are sold.
WIP inventory also represents real money sitting on the factory floor. According to the U.S. Census Bureau’s Manufacturers’ Shipments, Inventories, and Orders (M3) survey, U.S. manufacturers held about $272.4 billion in work-in-process inventory as of June 2026.
For accurate books, WIP must be measured under Generally Accepted Accounting Principles (GAAP). The Financial Accounting Standards Board (FASB) requires inventory, including WIP, to be measured at the lower of cost and net realizable value. That rule applies to companies using first in, first out (FIFO) or average cost.
Getting this classification right matters beyond bookkeeping. Overstated WIP inflates your assets and can hide production problems, while understated WIP can distort margins and mislead lenders or investors. Sound inventory accounting strategies keep these figures current, so your reported assets and margins stay reliable.
Why does work in process inventory management matter?
Managing WIP inventory well pays off across both operations and finance. Here are four benefits worth tracking.
1. Enhanced production efficiency
Tracking WIP inventory lets you follow items through each stage, spot bottlenecks early, reduce lead times, and minimize downtime. Real-time visibility turns a guessing game into a measurable process.
When you can see where every job stands, you rebalance labor and machine time before a slow station backs up the whole line. That kind of control shows up in the numbers. Grill Works Inc. reached a 99% on-time delivery rate and cut order cycle times to an average of 3.9 days with Fishbowl.
2. Better customer service
Accurate WIP data helps you predict completion dates, give customers reliable delivery estimates, and fulfill orders on time. When you know exactly where each job stands, you set promises you can actually keep.
Reliable dates also cut down on the status calls and expedite fees that erode both margins and goodwill. A customer who gets an accurate estimate up front is far more likely to order again.
3. Improved cost control
WIP tracking gives you clear visibility into production costs and tells you about manufacturing productivity, so you can prevent overproduction and waste. Knowing the true cost of goods in production also helps you price accurately and protect margins.
Prince Michel Vineyard & Winery cut the time to calculate cost to manufacture from six months after year-end to immediately upon manufacture, while improving accuracy by more than 10%. That shift from an annual guess to a real-time figure lets a team catch cost overruns while they can still act on them.
4. More accurate financial reporting
WIP inventory is a significant portion of your assets, so up-to-date records support accurate financial statements and GAAP compliance. Stale or estimated WIP values are a common source of restatements and audit friction, which makes current data worth the effort.
Reporting limitations shouldn’t box you in. Fishbowl AI Insights lets teams generate custom dashboards and reports in plain language, without SQL or custom report requests.
What are the best practices for WIP inventory management?
A few habits keep WIP data accurate and useful. Consider these four practices.
1. Implement real-time tracking
Barcode scanners, RFID tags, and IoT sensors capture movement as it happens. That means your WIP counts reflect reality instead of yesterday’s snapshot. Scanning at each stage also builds a timestamped trail you can use to measure how long items dwell between workstations.
2. Standardize processes
Clear procedures for data entry and quality control keep records consistent across shifts and operators. Standard steps also make it easier to train new staff and audit your numbers.
3. Analyze workflow regularly
Review your production flow often to spot delays and bottlenecks, then optimize how you assign labor and material. Small adjustments compound into shorter cycle times. Comparing WIP levels across products or lines also reveals which items tie up the most cash, so you can prioritize the fixes that free up working capital first.
4. Integrate inventory management systems
Connecting your tools gives you live insight across production, so data flows without manual re-entry. Purpose-built manufacturing inventory management software ties tracking, costing, and reporting into one system. When production data and accounting share a single source of truth, your WIP values stay accurate without a separate reconciliation step at close.
Optimize your WIP inventory management with Fishbowl
Fishbowl’s inventory management software offers real-time tracking and analytics, including the Work in Progress (WIP) report, so you always know the value of goods in production. It gives small and midsize manufacturers this level of control without the cost and complexity of an ERP project.
Fishbowl integrates with QuickBooks to keep your operations and accounting in sync, supporting clean COGS and a faster close. Because the same data drives both the shop floor and the ledger, your WIP values stay consistent from the production line to the balance sheet.
Book a Demo to see how Fishbowl fits your production process.
Frequently asked questions about work in process inventory
What is the difference between work in process and raw materials inventory?
Raw materials inventory is the unmodified inputs you buy to make products, such as steel, fabric, or components sitting in storage. Work in process inventory begins the moment those materials enter production and take on labor and overhead. In short, raw materials are inputs waiting to be used, while WIP is those same inputs partway through becoming finished goods. Once production finishes, the items become finished goods inventory.
How do you calculate ending work in process inventory?
Use this formula: Ending WIP = Beginning WIP + Manufacturing costs − cost of goods manufactured (COGM). Start with the WIP value carried over from the prior period, add the manufacturing costs incurred during the period, then subtract the COGM for goods completed. The same formula works whether you calculate WIP per accounting period or per job in a job-order setup. Consistent inputs give you a reliable ending value each time.
What are WIP days and why do they matter?
WIP days estimate roughly how long items sit in production before becoming finished goods. You calculate them by comparing average WIP inventory to your cost of goods manufactured over a period, then scaling the result to days. Lower WIP days generally point to a leaner, faster production flow with less cash tied up on the floor. Higher WIP days can signal bottlenecks, so tracking the trend over time helps you catch slowdowns early.
Is work in process inventory an asset?
Yes. Work in process inventory is a current asset, reported under the inventory line on your balance sheet. It holds the materials, labor, and overhead already invested in goods that are not yet finished. Those costs stay classified as an asset until production wraps and the goods sell, at which point they move to cost of goods sold. Because it represents real value, WIP belongs in your reported assets.
How is work in process different from finished goods inventory?
Work in process inventory is unfinished and cannot be sold yet, because the items are still moving through production. Finished goods inventory is complete, inspected, and ready to ship to customers. The practical difference is readiness: WIP still needs labor or components to reach completion, while finished goods only need a buyer. On the balance sheet, both are current assets, but they represent different stages of the production cycle.