CA Intermediate · Cost and Management Accounting

Unit & Batch Costing for CA Intermediate Cost and Management Accounting

Unit costing finds cost per unit of a single, uniform product using a cost sheet. Batch costing finds cost per batch of identical units, then per unit. EBQ is the batch size that minimises total set-up and carrying cost. Solve by building a cost sheet in order, then dividing by units.

What this chapter covers

This chapter covers three linked ideas from Paper 4. Unit costing (also called single or output costing) is used where one uniform product is made, such as bricks, cement or coal. You prepare a cost sheet that collects costs under standard heads and divides by units produced. Batch costing is used where identical units are made in lots, such as garments, medicines or components. Each batch is treated like a job, and its cost is divided by the batch quantity. Economic Batch Quantity (EBQ) asks how large each batch should be.

The chapter builds on your earlier work in the paper: classification of cost, material, labour and overhead treatment, and the cost sheet format. If those are weak, unit costing will feel hard. It also leads into job costing, process costing and later topics like standard costing and budgeting, because all of them use the same cost heads.

The chapter is practical. Almost every question is a numerical. You are given data, and you must arrange it correctly, treat items like scrap, stock and abnormal loss properly, and reach a per-unit figure or a batch size.

This chapter is worth the effort because it is largely formula-and-format work with little theory to memorise, so careful practice converts directly into marks. Numerical questions on this chapter may be asked as MCQs or as descriptive questions, so practise both the quick calculation and the full written format. There is no negative marking for wrong MCQ answers. The cost sheet skill also carries into other chapters, so time spent here pays back across the paper.

Unit & Batch Costing: topics in the order to study them

1Unit Costing (Single or Output Costing)Start here because it teaches the cost sheet layout and cost heads that the other two topics reuse.
2Batch CostingIt applies the same cost sheet to a lot of identical units, so it comes once you are comfortable with unit costing.
3Economic Batch Quantity (EBQ)It needs batch costing ideas of set-up cost and carrying cost, so study it last.

How to prepare Unit & Batch Costing

Prepare this chapter by practising the format first, then the variations, then the formula.

Learn the standard cost sheet order: direct material, direct labour, direct expenses, prime cost, factory overheads, gross factory cost, adjustment for opening and closing work-in-progress to reach works cost, office overheads, cost of production, then selling and distribution overheads, cost of sales and profit.
Solve unit costing problems with only direct data first, then add stock of raw material, work-in-progress and finished goods adjustments.
Practise the rules for losses and by-products: the cost of normal loss is borne by the good units, net of scrap value; abnormal loss is valued at cost like good units and written off to Costing Profit & Loss; the credit for scrap, or the net realisable value of a by-product (of small value), is deducted from the relevant cost (material or works cost) or treated as other income, as the question instructs.
Do batch costing problems by finding total cost of the batch, then cost per unit, and then price or profit on the batch.
Learn the simple EBQ formula: EBQ = √(2DS ÷ C), where D is annual demand, S is set-up cost per batch and C is carrying cost per unit per year. This is the form normally used in batch costing. It assumes each batch is received all at once. Practise questions where C is given as a percentage of unit cost.
Then learn the finite production rate form: EBQ = √(2DS ÷ (C × (1 − d ÷ p))), where d is the demand (usage) rate and p is the production rate, both in the same time unit, and p is greater than d. Use it only when the question gives a production rate and units are added to stock gradually while production runs. If no production rate is given, use the simple form.
Write each answer with working notes for stocks, loss and overhead rates, because step marks are given for them.
Finish with timed mixed practice and a quick check of units, since many errors come from wrong quantity figures.

Common mistakes in Unit & Batch Costing

Putting items in the wrong place in the cost sheet
Fix: Write the cost sheet skeleton first, then place each given figure under its head before calculating.
Dividing by units produced instead of units sold, or the reverse
Fix: Use units produced for cost of production per unit and units sold for cost of sales per unit, and state which you used.
Ignoring opening and closing stock adjustments
Fix: Underline every stock figure while reading and add a working note for each adjustment.
Using the wrong carrying cost in EBQ
Fix: Convert it to rupees per unit per year first, then apply the formula.
Treating set-up cost as a per-unit cost in EBQ
Fix: Remember S is a cost for each batch, not each unit, and D is annual demand in units.
Forgetting to show working notes
Fix: Show each calculation line by line so you earn step marks even if one figure is wrong.

Last-day revision: Unit & Batch Costing

Unit costing suits a single uniform product, such as bricks, cement or coal.
The cost sheet runs from prime cost to gross factory cost to works cost to cost of production to cost of sales to profit.
Prime cost = direct material + direct labour + direct expenses.
Gross factory cost = prime cost + factory overheads. Works cost = gross factory cost + opening WIP − closing WIP. Deduct scrap or by-product realisable value where the question instructs.
Cost of production = works cost + office/administration overheads. The WIP adjustment is made in reaching works cost. The credit for scrap or by-product is deducted from the relevant cost (material or works cost) as the question instructs, so do not repeat it here. For losses: the cost of normal loss stays in the good units (net of scrap value), while abnormal loss is valued at cost and written off to Costing Profit & Loss.
Cost of goods sold = opening finished goods + cost of production − closing finished goods.
Cost of sales = cost of goods sold + selling and distribution overheads.
Cost per unit = total cost ÷ units produced (or sold, for cost of sales).
Batch costing treats each batch like a job and divides batch cost by units in the batch.
Set-up cost is spread over the units in a batch, so larger batches lower set-up cost per unit.
Simple EBQ = √(2DS ÷ C), with D annual demand, S set-up cost per batch, C carrying cost per unit per year. This is the form normally used in batch costing. It assumes constant demand and that each batch is received all at once.
If a question gives a production rate p and a demand rate d (same time unit, p greater than d), use EBQ = √(2DS ÷ (C × (1 − d ÷ p))). Stock builds up only gradually while production runs, so the adjusted form gives a larger batch than the simple form.
In the simple model, total set-up cost equals total carrying cost at EBQ, where carrying cost = C × Q ÷ 2. In the finite production rate model, carrying cost = C × Q × (1 − d ÷ p) ÷ 2, because average stock is Q × (1 − d ÷ p) ÷ 2, which is lower than Q ÷ 2. At EBQ this carrying cost equals total set-up cost (D ÷ Q) × S.
Number of batches per year = D ÷ EBQ.
Check that all costs and units use the same time period before dividing.

Unit & Batch Costing practice questions

Unit & Batch Costing in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Unit & Batch Costing: frequently asked questions

How is unit costing different from batch costing?

Unit costing is for one continuous, uniform product, so total cost is divided by total output. Batch costing is for lots of identical units made together, so you find the cost of each batch first and then divide by the batch quantity.

What is the EBQ formula for CA Intermediate?

EBQ = √(2DS ÷ C). D is annual demand in units, S is set-up cost per batch and C is carrying cost per unit per year. It gives the batch size at which total set-up and carrying cost is lowest.

Can I score well in this chapter without much theory?

Yes, because most questions are numerical. Learn the cost sheet format and the EBQ formula, then practise varied problems. Short theory points such as where each method applies can still be asked in MCQs.

Why does EBQ balance set-up and carrying cost?

Larger batches reduce the number of set-ups but increase stock held, which raises carrying cost. Smaller batches do the opposite. The lowest total cost occurs where total set-up cost equals total carrying cost, with carrying cost measured on the average stock actually held. In the finite production rate model that average stock is lower than half the batch size.