Cost and Management Accounting · Process & Operation Costing
Operation Costing: Meaning, Method and Cost Calculation
Updated 4 October 2026 · Fact-checked
Operation costing is a method used when mass production passes through distinct operations. You collect cost for each operation, divide it by the units that go through that operation to get the cost per unit of the operation, and add the operation costs to get the cost of the product or batch.
Understand Operation Costing
Operation costing is a costing method for mass or repetitive production where the work is done in a series of distinct operations. It is a refinement of process costing and batch or job costing. Cost is first collected operation by operation, not process by process.
Think of a factory making garments, nuts and bolts, or engineering components. Each unit goes through cutting, stitching, finishing and so on. The cost of each operation is found separately. Material is usually charged to the batch or lot that uses it. Conversion cost (labour and overheads) is collected for each operation.
The cost per unit of an operation is the total cost of that operation divided by the units that pass through it. The cost of a product is the sum of the operation costs it actually goes through. Different products may pass through different operations, so they get different costs.
Process costing vs operation costing. A process is a stage of manufacture that is usually a distinct department or stage and has its own account. An operation is a specific step of work, often within a process or department. Process costing finds the average cost per unit of a process. Operation costing finds the cost per unit of each operation and builds the product cost from them. In operation costing, material cost is generally tracked by batch or product, while in process costing it is averaged within the process.
Uses. It helps control cost by operation, fix the cost of products that follow different routes, and compare actual operation cost with standard. It suits industries such as textiles, footwear, electronics assembly, and engineering and chemical-type batch work.
Key rules to remember
- Cost per unit of an operation
- Cost per unit of operation = Total cost of the operation ÷ Units processed in the operation
- Use units that actually pass through that operation. Normal loss adjustments, if given, come first.
- Operation cost for a batch
- Operation cost for a batch = Cost per unit of operation × Units of the batch passing through it
- Charge only the operations the batch actually goes through.
- Total cost of a product or batch
- Total cost = Material cost + Σ (Operation cost per unit × Units)
- Σ means the sum over all operations used. Material is normally charged directly to the batch.
- Overhead rate per unit for an operation
- Overhead rate = Overhead of the operation ÷ Units (or hours) of the operation
- Use the same base for absorption as given in the question, such as machine hours or units.
How to solve Operation Costing questions
Follow this order for any operation costing question. It keeps the working clear and earns step marks.
- 1List the operations in sequence and note which product or batch passes through which operation.
- 2Find the units entering and leaving each operation. Adjust for normal loss, scrap value or abnormal loss as the question says.
- 3Collect cost for each operation: labour, direct expenses and overheads (absorbed or apportioned as given).
- 4Compute cost per unit for each operation: operation cost ÷ units processed.
- 5Charge direct material to the batch or product that uses it, and compute material cost per unit.
- 6Add material cost and the cost per unit of every operation the product passes through.
- 7Multiply by units to get total cost. Add profit if selling price is asked.
- 8Show a short working note for each operation and state the final answer clearly.
Quickest way: Operation table method
When to use it: Use it for numericals with several operations and more than one product or batch. It also saves time on MCQs.
- Draw a small table with operations as rows: total cost, units, cost per unit.
- Fill cost per unit first. Everything else is a multiplication or addition.
- For each product, tick the operations it uses and add only those rates.
- For MCQs, check which operations apply before calculating. Options often include the sum of all operations as the wrong answer.
- In written answers, give the table, then one line for each product's total cost. This format earns step marks even if a number slips.
Common mistakes in Operation Costing
Adding the cost of all operations to every product.
Students treat it like process costing where all costs flow through.
Fix: Tick the operations each product actually passes through and add only those.
Dividing operation cost by the wrong units, such as input instead of units processed.
Units differ between operations after losses or rejections.
Fix: Write units processed beside each operation before dividing.
Averaging material cost across all products.
Process costing habit of averaging everything within a process.
Fix: Charge material to the specific batch or product that consumed it, unless the question says otherwise.
Mixing up process costing and operation costing in theory answers.
Both are for continuous or mass production, so they seem the same.
Fix: State that process costing averages cost per process, while operation costing finds cost per operation and builds product cost from the operations used.
Ignoring scrap value or normal loss when computing operation cost.
Students rush to the division step.
Fix: Read the question for loss and scrap. Deduct scrap realisation from the operation cost and use net units as instructed.
Worked examples
Example 1
A factory has two operations. Operation 1 (cutting) cost ₹60,000 for 3,000 units processed. Operation 2 (finishing) cost ₹45,000 for 1,500 units processed. Product A (1,000 units) passes through both operations. Product B (2,000 units) passes only through cutting. Direct material is ₹20 per unit for A and ₹15 per unit for B. Find the total cost of each product.
Show the solution
- Cost per unit of cutting = ₹60,000 ÷ 3,000 = ₹20.
- Cost per unit of finishing = ₹45,000 ÷ 1,500 = ₹30.
- Product A cost per unit = material ₹20 + cutting ₹20 + finishing ₹30 = ₹70.
- Product A total = ₹70 × 1,000 = ₹70,000.
- Product B cost per unit = material ₹15 + cutting ₹20 = ₹35.
- Product B total = ₹35 × 2,000 = ₹70,000.
Answer: Product A costs ₹70 per unit (total ₹70,000). Product B costs ₹35 per unit (total ₹70,000).
Example 2
In a plant, Operation X cost ₹1,80,000 for 6,000 units processed. Operation Y cost ₹96,000 for 4,000 units processed. Operation Z cost ₹1,20,000 for 2,000 units processed. A batch of 500 units passes through X and Z only. Material cost for the batch is ₹25,000. Find the batch cost and cost per unit.
Show the solution
- Cost per unit of X = ₹1,80,000 ÷ 6,000 = ₹30.
- Cost per unit of Z = ₹1,20,000 ÷ 2,000 = ₹60.
- Operation X cost for batch = ₹30 × 500 = ₹15,000.
- Operation Z cost for batch = ₹60 × 500 = ₹30,000.
- Total batch cost = ₹25,000 + ₹15,000 + ₹30,000 = ₹70,000.
- Cost per unit = ₹70,000 ÷ 500 = ₹140.
Answer: Total batch cost is ₹70,000 and cost per unit is ₹140. Operation Y is not charged because the batch does not pass through it.
Exam tips
- In theory questions, always give a clear difference from process costing and one example such as textiles or engineering components.
- In numericals, draw the operation table first. It scores step marks and prevents unit errors.
- Read which operations each product uses. This is the most common trap in MCQs.
- Check for loss, scrap or rejection in an operation before dividing the cost.
- Write the final answer with units and the rupee sign, and state cost per unit and total cost if both are asked.
Practice questions from Process & Operation Costing
- Which of the following is a characteristic of operation costing as distinguished from process costing?
- In process costing, the statement of equivalent production is prepared mainly to:
- Sharda Chemicals puts 10,000 kg of material into Process I at a cost of Rs 2,00,000. Labour and overheads are Rs 1,00,000. Normal loss is 10…
- Ganga Chemicals starts 5,000 kg of material in Process I at a cost of ₹2,00,000. Other process costs are ₹50,000. Normal loss is 10% of inpu…
- Which statement best describes operation costing as used for batch production of items such as garments or auto parts?
Operation Costing: frequently asked questions
What is operation costing in simple words?
It is a method where you find the cost of each separate operation in production and add up the operations a product goes through. It is used for mass production with distinct operations, such as garments or components.
What is the difference between process costing and operation costing?
Process costing finds the average cost per unit of each process and passes it on. Operation costing finds the cost per unit of each operation and builds a product's cost from only the operations it uses. Material is usually charged to the batch in operation costing.
How do you calculate cost in operation costing?
Divide the total cost of each operation by the units processed in it to get a rate per unit. Then add the material cost and the rates of the operations the product passes through. Multiply by units for the total.
Is operation costing asked as a numerical in the exam?
It can appear as a short numerical or as an MCQ on cost per unit by operation. It can also be asked as a theory question on meaning, features and differences, so prepare both.