Work in Process Calculator
Count and value the units still on the floor at the end of a period.
In short
Count and value the units still on the floor at the end of a period.
Formula: Work in process = Units started − Units completed − Units scrapped; Value = Work in process × Cost invested per unit
What this calculator does
A count balance. The value is shown only when the user enters a cost per unit; no standard cost is assumed.
Use it to turn Currency, Units started in the period, Units completed in the period, Units scrapped in the period (optional), and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Currency
- — Amounts are shown in the currency you pick. No exchange rate is applied..
- Units started in the period
- — number value.
- Units completed in the period
- — number value.
- Units scrapped in the period (optional)
- — Optional. Leave at 0 to exclude it from the result..
- Cost invested in each unit still in process (optional)
- — Optional. Leave at 0 to exclude it from the result. Your own figure. Used only to value the work in process..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
Work in process = Units started − Units completed − Units scrapped; Value = Work in process × Cost invested per unit.
Inputs used: Currency, Units started in the period, Units completed in the period, Units scrapped in the period (optional), Cost invested in each unit still in process (optional).
Edge handling: Units started in the period is required.; Units started in the period cannot be negative.; Units started in the period must be no more than 1000000000000.; Units completed in the period is required.; Units completed in the period cannot be negative..
Worked example
What is still on the floor at the end of the period
- Start with Currency: USD, Units started in the period: 5000, Units completed in the period: 4600, Units scrapped in the period (optional): 60, Cost invested in each unit still in process (optional): 18.
- Apply the method: Work in process = Units started − Units completed − Units scrapped; Value = Work in process × Cost invested per unit.
- Only the units you entered are counted; opening work in process belongs in the units started.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this work in process calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: Massachusetts Institute of Technology — 2.854 Introduction to Manufacturing Systems
Last reviewed:
Common questions
Where does this formula come from?
MIT OpenCourseWare 2.854 Introduction to Manufacturing Systems — throughput is output per unit of time, cycle time is run time divided by the units produced, line capacity is set by the slowest station, and balance efficiency compares total work content with the number of stations multiplied by the longest station time. See the source link on this page.
What kind of calculation is this?
What went in, less what came out and what was written off, optionally valued at the cost already invested in each unit. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
Arithmetic over the figures entered — it cannot tell whether the measurements behind them are right. A measured result, an industry benchmark and an organisation's target are three different things; only the entered figures are used. A count at a point in time, not an average inventory, and not a flow-time calculation.
How do I use the Work in Process Calculator?
Enter the required values for Currency, Units started in the period, Units completed in the period, Units scrapped in the period (optional), Cost invested in each unit still in process (optional). The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Work in Process Calculator use?
Work in process = Units started − Units completed − Units scrapped; Value = Work in process × Cost invested per unit The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the Work in Process Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
What went in, less what came out and what was written off, optionally valued at the cost already invested in each unit.
The question it answers: How fast is this line really going, how long does one unit take, and how long does an order take end to end?
The formula
Work in process = Units started − Units completed − Units scrapped; Value = Work in process × Cost invested per unit
- S — Units started
- (count). Units started in the period, including any opening work in process.
- C — Units completed
- (count). Units finished in the period.
- X — Units scrapped
- (count). Optional. Units written off in the period.
- c — Cost per unit in process
- (currency). Optional. The user's own figure, used only to value the work in process.
Units: Counts in; a count out, and a currency value when a cost is entered.
What kind of calculation this is
Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.
Method
A count balance. The value is shown only when the user enters a cost per unit; no standard cost is assumed.
Assumptions built into the result
- Mathematical: Every quantity, time and rate is the figure the user entered, measured over the period they describe.
- Mathematical: Times and counts refer to the same period and the same resource.
- Mathematical: Opening work in process is included in the units started.
Figures this calculator will never guess for you
- No industry benchmark, target utilisation or target availability is supplied or applied.
- No shift length, break allowance, downtime allowance or standard rate is assumed.
- Optional components are excluded from the result when left at zero.
Limitations
- Arithmetic over the figures entered — it cannot tell whether the measurements behind them are right.
- A measured result, an industry benchmark and an organisation's target are three different things; only the entered figures are used.
- A count at a point in time, not an average inventory, and not a flow-time calculation.
Source and version
- Standard or reference
- Manufacturing systems — throughput, cycle time, work in process and line balancing — MIT OpenCourseWare (MIT OpenCourseWare 2.854 Introduction to Manufacturing Systems — throughput is output per unit of time, cycle time is run time divided by the units produced, line capacity is set by the slowest station, and balance efficiency compares total work content with the number of stations multiplied by the longest station time.)
- Published source
- Massachusetts Institute of Technology — Fall 2016
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Academic
- Applies to
- Currency
- Amounts stay in the currency you choose; no exchange rate is applied.
Cite this page
Free Calculator. (2026, September 16). Work in Process Calculator. https://freecalculator.tech/tools/work-in-process-calculator
"Work in Process Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/work-in-process-calculator.
Work in Process Calculator — Free Calculator, https://freecalculator.tech/tools/work-in-process-calculator
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