Cost accounting: elements of cost

In short

Elements of cost are the basic heads under which every rupee a business spends on making a product or giving a service is grouped — material, labour and expenses, each split into direct and indirect. Build them up in sequence and you get prime cost → works (factory) cost → cost of production → cost of sales → sales, which is exactly what a cost sheet shows and what pricing, tenders, valuation of stock and cost control all rest on. This is the foundation unit of B.Com / M.Com cost accounting, CA/CMA Foundation and Inter, and it carries the highest-marks practical question in most university papers (cost sheet, tender/estimate). In interviews for costing, FP&A, plant finance and audit roles (Tata Steel, L&T, Maruti, Asian Paints, ITC, Big-4 cost assurance), candidates are asked to classify a cost and to say where it sits in the cost sheet.

Explained

Cost, costing and the basic vocabulary

• Cost: the amount of expenditure, actual or notional, incurred on or attributable to a given thing (CIMA). It is always *cost of what* — a product, a job, a process, a service.
• Costing: the technique and process of ascertaining cost. Cost accounting records, classifies and reports it; cost accountancy is the whole field including cost control and cost audit.
• Cost unit: the unit of product or service in which cost is expressed — tonne of cement, litre of paint, SKU, kWh of power, passenger-km, bed-day in a hospital, call in a BPO.
• Cost centre: a location, person or equipment for which costs are collected — a machine shop (impersonal) or a foreman's area (personal); profit centre and cost centre differ in that a profit centre is also charged with revenue.
• Cost object: anything for which a separate cost measurement is wanted (product, customer, contract, department).
• Cost driver: the factor that causes a cost to change (machine hours, number of setups, labour hours).
• Cost allocation = charging a whole cost to one cost centre; apportionment = spreading a common cost over several centres on a fair basis; absorption = loading cost centre overhead onto cost units by a rate.

The three elements and the direct/indirect split

Every cost is first split by nature into Material, Labour and Expenses; each of those is then either Direct (traceable to a cost unit economically and conveniently) or Indirect (not so traceable, hence pooled as overhead).

• Direct material: material that becomes part of the product or is identifiably consumed in it — steel in a car body, cotton yarn in fabric, cement and sand in a contract, primary packing material (bottle, blister pack).
• Indirect material: consumables and small items not traceable per unit — lubricants, cotton waste, grinding wheels, small tools, secondary/transport packing, cleaning material.
• Direct labour (direct wages): wages of workers who convert the material — machine operators, assembly line workers, weavers, masons on a site; includes the direct worker's overtime at normal rate.
• Indirect labour: supervisors, storekeepers, maintenance crew, timekeeper, sweepers, idle-time wages, overtime premium (unless caused by a specific job).
• Direct expenses (chargeable expenses): expenses other than material and labour directly traceable to a job — hire of a special machine for one job, cost of a specific design/drawing, royalty paid per unit produced, job-specific carriage inward, tool made for one order, sub-contracting charges.
• Indirect expenses: rent, insurance, power, depreciation, telephone, audit fee, advertising — everything else.
• Overhead = indirect material + indirect labour + indirect expenses, grouped by function into factory/works overhead, administration (office) overhead, selling overhead and distribution overhead.
• Conversion cost = direct labour + direct expenses + factory overhead, i.e. the cost of converting material into finished goods.

Build-up of cost: the cost sheet sequence

1. Opening stock of raw material + purchases + carriage inward/freight/duty − closing stock − returns − scrap of material sold = Direct material consumed.
2. Prime cost = direct material consumed + direct wages + direct (chargeable) expenses.
3. + Factory/works overhead (indirect factory items; power, factory rent, factory depreciation, works manager's salary, repairs to plant, factory insurance).
4. Adjust work-in-progress: + opening WIP − closing WIP (if WIP is valued at works cost) → Works cost / Factory cost. Sale value of factory scrap is deducted here if not already netted off material.
5. + Administration overhead (office rent, directors' fees, accounts/legal/audit, office salaries and stationery, office depreciation) → Cost of production.
6. Adjust finished goods: + opening stock of finished goods − closing stock of finished goods → Cost of goods sold (cost of sales of goods produced and sold).
7. + Selling and distribution overhead (salesmen's salary and commission, advertising, showroom rent, bad debts, secondary packing, delivery van running, warehouse of finished goods) → Cost of sales.
8. + Profit = Sales. Equivalently Profit = Sales − Cost of sales.

Conventions worth remembering: finished goods closing stock is valued at cost of production per unit (of the current period, unless FIFO/weighted average is specified); WIP at works cost (or as the question directs); and non-cost items are excluded from the cost sheet.

Items excluded from cost accounts (purely financial / appropriations)

• Appropriations of profit: income tax, dividend paid, transfer to reserves, donations and charity (unless trade-related), goodwill written off, preliminary expenses written off.
• Pure financial charges and incomes: interest on capital and loans (treated as finance cost, normally excluded from cost; some syllabi allow interest on borrowed capital as a cost — state the assumption), loss on sale of assets or investments, profit on sale of fixed assets, dividend and interest received, rent received, transfer fees.
• Abnormal items: abnormal wastage, abnormal idle time, loss by fire or theft, cost of abnormal rejections, penalties — charged to costing P&L, not to the cost sheet.
• A cost reconciliation statement reconciles profit as per cost accounts with profit as per financial accounts for these exclusions, under/over-absorption of overhead and different stock valuation bases.

Other classifications examined alongside elements

• By nature/element: material, labour, expenses (as above).
• By function: production/manufacturing, administration, selling, distribution, research and development.
• By traceability: direct and indirect.
• By behaviour: fixed (rent, salaries — total constant, per-unit falls with volume), variable (material, piece-rate wages — total moves with volume, per-unit constant), semi-variable/mixed (electricity, telephone, repairs — split by high-low or least squares); step cost (one supervisor per shift added in blocks).
• By controllability: controllable (by the centre's manager) and uncontrolled/uncontrollable (apportioned head-office cost).
• By normality: normal cost (expected at a given output, forms part of cost) and abnormal cost (charged to P&L).
• By time: historical (post-facto), predetermined/standard, and estimated cost.
• For decisions: relevant vs irrelevant, marginal, differential/incremental, opportunity cost (benefit of the next best option forgone), sunk cost (past, irreversible — ignore), imputed/notional (rent of own building), out-of-pocket vs book cost, replacement cost, shut-down cost, avoidable vs unavoidable, committed cost.
• Product vs period cost: product cost attaches to units and sits in inventory until sold (manufacturing costs); period cost is expensed in the period (selling, admin). This matters for inventory valuation.

Indian standards, statute and practice

• Cost Accounting Standards (CAS 1 to CAS 24) are issued by the Institute of Cost Accountants of India (ICMAI). Those tied to this topic: CAS 6 Material Cost, CAS 7 Employee Cost, CAS 10 Direct Expenses, CAS 3 Production and Operation Overheads, CAS 9 Packing Material Cost, CAS 11 Administrative Overheads, CAS 12 Repairs and Maintenance, CAS 14 Pollution Control Cost, CAS 15 Selling and Distribution Overheads, CAS 22 Manufacturing Cost, CAS 24 Treatment of Revenue in Cost Statements. (Numbering is stable, but check ICMAI for the latest revision of any standard before quoting it in practice.)
• CAS 4 gives cost of production for captive consumption — used for GST/excise valuation of goods transferred to another unit; the certificate states the cost of production, and the assessable value is that cost × 110% under the captive-consumption valuation rule (Rule 30 of the CGST Rules; earlier Rule 8 of the Central Excise Valuation Rules), so a cost accountant's certificate matters commercially.
• Companies Act 2013, section 148 with the Companies (Cost Records and Audit) Rules, 2014 requires specified regulated and non-regulated industries above turnover thresholds to maintain cost records in Form CRA-1 (which is organised element-wise, almost exactly as a cost sheet) and, above higher thresholds, to get a cost audit (CRA-2, CRA-3, CRA-4). Thresholds and the covered-industry lists have been amended more than once — verify the current rule before applying it.
• Material valuation interacts with AS 2 / Ind AS 2 Inventories: cost of inventory includes purchase price net of GST input tax credit, duties not recoverable, freight inward and handling, less trade discount and rebates; normal loss is absorbed in cost, abnormal loss is expensed. Cash discount is a financial item, trade discount a cost reduction.
• Under GST, recoverable input tax credit is not part of material cost; non-creditable tax is.

Key points

• Element of cost - material, labour and expenses; each further direct or indirect.
• Direct cost - economically and conveniently traceable to one cost unit; everything else is overhead.
• Prime cost - direct material + direct labour + direct expenses.
• Overhead - indirect material + indirect labour + indirect expenses, grouped as factory, administration, selling and distribution.
• Works/factory cost - prime cost + factory overhead ± WIP adjustment, less scrap realised.
• Cost of production - works cost + administration overhead; the rate used to value closing finished goods.
• Cost of goods sold - cost of production + opening finished goods − closing finished goods.
• Cost of sales - cost of goods sold + selling and distribution overhead; Sales − Cost of sales = Profit.
• Conversion cost - direct labour + direct expenses + factory overhead; cost of turning material into product.
• Primary packing - factory cost (protects the product); secondary packing - distribution overhead (for transport).
• Overtime premium and idle time - normally factory overhead; charged direct only if the job specifically caused it.
• Non-cost items - income tax, dividend, donations, interest, profit/loss on asset sale, abnormal losses — kept out of the cost sheet.
• Fixed vs variable - fixed total is constant and per-unit falls; variable per-unit is constant and total rises with output.
• Cost unit vs cost centre - unit is what cost is measured per; centre is where cost is collected.
• Sunk and opportunity cost - sunk is past and irrelevant; opportunity cost is the forgone benefit and is relevant to decisions.
• CAS 6, 7, 10, 3 - ICMAI standards on material, employee, direct expenses and production overheads.
• CRA-1 / section 148 - statutory element-wise cost records for notified industries under the Companies Act 2013.
• Tender/quotation - built on the cost sheet with overheads recovered as a percentage of wages or works cost, then profit added on cost or on sales as stated.

Formulas and examples

Example 1 — Full cost sheet. Sharma Engineering, month of September 2026: opening raw material ₹60,000; purchases ₹4,40,000; carriage inward ₹10,000; closing raw material ₹50,000; direct wages ₹2,00,000; royalty on production ₹20,000; factory overhead ₹1,50,000; opening WIP ₹40,000; closing WIP ₹55,000; sale of factory scrap ₹5,000; administration overhead ₹80,000; selling and distribution overhead ₹70,000; 10,000 units produced, opening finished stock nil, closing finished stock 1,000 units; sales ₹10,00,000.

Cost of production per unit = 8,90,000 ÷ 10,000 = ₹89. Profit per unit sold = 1,29,000 ÷ 9,000 ≈ ₹14.33; profit as % of sales = 12.9%.

Example 2 — Tender price using recovery percentages. Last year: direct material ₹5,00,000; direct wages ₹4,00,000; factory overhead ₹3,00,000; administration overhead ₹1,47,000 (works cost basis); selling overhead ₹1,00,000. A tender needs material ₹30,000 and wages ₹25,000. Material prices will rise 10% and wage rates 8%. Profit is to be 20% on selling price; selling overhead is recovered at the same % of works cost as last year.

• Factory overhead rate = 3,00,000 ÷ 4,00,000 = 75% of direct wages.
• Last year's works cost = 5,00,000 + 4,00,000 + 3,00,000 = ₹12,00,000 → administration = 1,47,000 ÷ 12,00,000 = 12.25% of works cost; selling = 1,00,000 ÷ 12,00,000 = 8.333% of works cost.
• Tender: material 30,000 × 1.10 = ₹33,000; wages 25,000 × 1.08 = ₹27,000 → prime cost ₹60,000.
• Factory overhead = 75% × 27,000 = ₹20,250 → works cost ₹80,250.
• Administration = 12.25% × 80,250 = ₹9,830.63; selling = 8.333% × 80,250 = ₹6,687.50 → cost of sales ₹96,768.13.
• Profit 20% on selling price = 25% on cost → profit = ₹24,192.03; tender price ≈ ₹1,20,960 (check: profit ÷ price = 24,192 ÷ 1,20,960 = 20%).

Example 3 — Classifying items.

Example 4 — Fixed, variable and semi-variable behaviour. A unit makes 2,000 pieces: material ₹40/unit (variable), labour ₹25/unit (variable), factory rent ₹30,000 (fixed), power ₹26,000 of which 60% varies with output.

• At 2,000 units: variable = (40 + 25) × 2,000 = ₹1,30,000; variable power = 0.60 × 26,000 = ₹15,600 → ₹7.80/unit; fixed = 30,000 + 10,400 = ₹40,400. Total = ₹1,86,000 → ₹93.00/unit.
• At 2,500 units: variable = 65 × 2,500 = ₹1,62,500; power variable = 7.80 × 2,500 = ₹19,500; fixed unchanged ₹40,400. Total = ₹2,22,400 → ₹88.96/unit.
• Cost per unit fell ₹4.04 purely because fixed cost spread over more units — total fixed cost did not change.

Example 5 — Semi-variable split by high-low, then cost sheet effect. Maintenance cost was ₹46,000 at 8,000 machine hours and ₹58,000 at 12,000 hours.

• Variable rate = (58,000 − 46,000) ÷ (12,000 − 8,000) = ₹3 per machine hour.
• Fixed = 46,000 − 3 × 8,000 = ₹22,000 per month (check at high: 22,000 + 3 × 12,000 = ₹58,000 ✓).
• Budget for 10,000 hours = 22,000 + 30,000 = ₹52,000, which goes into factory overhead in the cost sheet.

Where it is used

• Manufacturing plant finance: monthly product cost sheets and standard cost cards in auto, cement, steel, paints and FMCG (Maruti Suzuki, Tata Steel, UltraTech, Asian Paints, Hindustan Unilever) for pricing, variance review and make-or-buy.
• Tendering and contracting: L&T, BHEL, EPC and government-supply tenders price bids by building material + labour + overhead recovery + margin, exactly as in Example 2.
• Statutory cost records and cost audit: companies in pharma, fertiliser, sugar, power, telecom and other notified sectors maintain CRA-1 element-wise records; practising cost accountants and Big-4 cost assurance teams test them.
• Transfer pricing and GST valuation: CAS-4 certificates for stock transferred between units of the same company for captive consumption.
• Services: cost per bed-day in hospitals, cost per passenger-km in transport, cost per seat in IT/BPO, cost per kWh in power — same elements, different cost unit.
• Job roles: cost accountant, costing/MIS executive, plant finance analyst, FP&A analyst, pricing analyst, management trainee (finance) — all tested on cost sheet preparation and classification.

Interview questions

• Q: What are the three elements of cost? A: Material, labour and expenses; each is further classified as direct (traceable to a cost unit) or indirect, and all indirect items together form overhead.
• Q: Give the sequence from prime cost to sales. A: Prime cost + factory overhead ± WIP = works cost; + administration overhead = cost of production; ± finished goods stock = cost of goods sold; + selling and distribution overhead = cost of sales; + profit = sales.
• Q: Is factory rent a direct or indirect cost? A: Indirect — it cannot be traced to a single unit, so it is factory overhead and is absorbed by units through an overhead rate.
• Q: How do you treat overtime wages of a direct worker? A: The normal-rate portion is direct wages; the overtime premium goes to factory overhead, unless the customer's urgent order caused it, when it is charged direct to that job.
• Q: Where does primary packing go, and where does secondary packing go? A: Primary packing (immediate container that protects the product) is a factory cost; secondary packing for transport is distribution overhead.
• Q: Which items are kept out of a cost sheet? A: Appropriations and pure financial items — income tax, dividend, donations, interest on capital, profit or loss on sale of assets — and abnormal losses, which go to the costing profit and loss account.
• Q: At what value is closing stock of finished goods shown in a cost sheet? A: At cost of production per unit of the current period (works cost + administration overhead ÷ units produced), unless FIFO or weighted average is specifically required.
• Q: What is conversion cost and why would a manager watch it? A: Direct labour + direct expenses + factory overhead — the cost of converting material into finished goods; it isolates factory efficiency from volatile material prices.
• Q: Difference between allocation, apportionment and absorption? A: Allocation charges a whole cost to one centre; apportionment splits a shared cost across centres on a fair basis; absorption loads centre overhead onto cost units via a rate.
• Q: Profit is 25% on cost — what is it as a percentage of sales? A: 20% — because if cost is 100, profit is 25 and sales 125, so 25/125 = 20%.
• Q: Is depreciation fixed or variable? A: Straight-line depreciation on time is fixed; depreciation charged on a units-of-production or machine-hour basis behaves as variable, so the method decides the behaviour.
• Q: Which law requires Indian companies to keep cost records element-wise? A: Section 148 of the Companies Act 2013 with the Companies (Cost Records and Audit) Rules, 2014, which prescribe Form CRA-1 for notified industries above turnover thresholds; the thresholds and industry lists have been amended, so the current rule should be checked.
• Q: Why can two companies report different costs for an identical product? A: Different overhead absorption bases, inventory valuation methods, treatment of abnormal items and whether interest and R&D are included in cost.

Common mistakes

• Adding opening and closing stock of finished goods at the works-cost stage instead of after administration overhead, and adjusting WIP in the wrong place.
• Valuing closing finished stock at works cost or at selling price instead of cost of production per unit.
• Treating carriage inward as selling expense and carriage outward as a factory cost — inward is part of material cost, outward is distribution.
• Including non-cost items (income tax, dividend, donations, interest, loss on sale of assets, abnormal loss) inside the cost sheet.
• Mixing up profit on cost with profit on sales in tender questions — 25% on cost equals 20% on sales.
• Applying last year's factory overhead percentage to the *revised* wages but forgetting to revise material and wage rates first, or recovering administration overhead on prime cost when the given basis was works cost.
• Saying fixed cost per unit is constant; it is total fixed cost that stays constant while cost per unit falls as output rises.

Related topics

• Material cost control: EOQ and inventory valuation · Labour cost and remuneration systems · Overheads: allocation, apportionment and absorption · Job, batch and contract costing · Marginal costing and break-even analysis · Budgeting and standard costing.