Overheads represent the indirect costs incurred during production or service delivery that cannot be directly traced to a specific cost unit. Unlike direct materials and direct labor, overheads are common costs shared across multiple products, departments, or processes. They include indirect materials (lubricants, consumables), indirect labor (supervisors, cleaners, maintenance staff), and indirect expenses (rent, insurance, power, depreciation, office salaries). Overheads are essential for operations but do not physically become part of the finished product. Proper classification, allocation, apportionment, and absorption of overheads are critical for accurate product costing, pricing decisions, and profitability analysis. Mismanagement of overheads can distort cost figures, leading to incorrect strategic choices.
Over Absorption of Overheads
Over absorption (or over-recovery) of overheads occurs when the overheads charged to production (through predetermined absorption rates) exceed the actual overheads incurred during a period. This situation arises when actual activity level is higher than estimated, actual expenses are lower than budgeted, or inefficient utilization leads to over-recovery. For example, if budgeted overhead is ₹1,00,000 for 10,000 machine hours (₹10 per hour), but actual overhead is ₹90,000 for 10,500 hours, absorbed overhead = ₹1,05,000 (10,500 × ₹10), resulting in over absorption of ₹15,000. Over absorption is adjusted at period end by crediting the over-absorbed amount to the costing profit and loss account or by reducing product costs.
Treatment of Over Absorption of Overheads:
1. Transfer to Costing Profit & Loss Account
The entire amount of over-absorbed overhead is transferred directly to the Costing Profit & Loss Account as a credit (negative expense). This method is simplest and most commonly used when the over-absorption is small or due to abnormal circumstances like windfall gains or sudden demand spikes. It treats over-absorption as a period gain rather than adjusting product costs. For example, if over-absorption is ₹50,000, the Costing P&L Account is credited, increasing reported profit. However, this method violates the matching principle because product costs remain inflated (they absorbed higher overhead than actually incurred). It is acceptable for internal reporting when adjustments are immaterial. Annual financial statements typically use this method after reconciling with financial accounts.
2. Carry Forward to Next Period
The over-absorbed overhead is carried forward as a deferred credit to the next accounting period. This method is used when production is seasonal or cyclical, and overhead rates are designed to smooth costs across periods. The over-absorbed amount is shown as a reserve or deferred credit in the balance sheet. In the next period, it is adjusted against that period’s under-absorption or reduces the predetermined rate. This treatment is common in industries with long production cycles (shipbuilding, construction) where annual accounting periods are arbitrary. However, it violates the periodicity concept and is not accepted under standard accounting principles (GAAP/IFRS) for external reporting. It is used only for internal cost management purposes.
3. Adjustment by Supplementary Rate
The over-absorbed amount is adjusted by revising the overhead absorption rate (supplementary rate) and crediting it to the cost of goods sold, work-in-progress, and finished goods inventory in proportion to their share of absorbed overhead. Formula: Supplementary Credit Rate = (Over-absorption Amount / Total Absorbed Overhead) × 100. Each cost center’s product cost is reduced by this percentage. This method is most accurate as it corrects the actual cost of production, work-in-progress, and closing stock. It is used when over-absorption is material and product costs must reflect actual expenses for pricing or inventory valuation. However, it requires detailed calculations and is time-consuming. Standard costing systems often use supplementary adjustments at year-end for financial reporting compliance.
4. Write-Off to Cost of Goods Sold (COGS)
The over-absorbed overhead is deducted entirely from the Cost of Goods Sold (COGS) account. This treatment assumes that most of the period’s production has been sold, making inventory adjustment unnecessary. It is simpler than supplementary rate method but less accurate when significant work-in-progress or finished goods inventory exists. For example, if COGS is ₹5,00,000 and over-absorption is ₹50,000, adjusted COGS becomes ₹4,50,000, increasing gross profit. This method is acceptable under marginal costing but not under absorption costing for external reporting. Cost accountants use it for monthly or quarterly statements when inventory levels are stable. At year-end, a full supplementary adjustment is preferred for statutory compliance.
Methods of Overhead Absorption:
1. Direct Material Cost Method
The overhead absorption rate is calculated as a percentage of direct material cost. Formula: (Budgeted Overhead / Budgeted Direct Material Cost) × 100. For example, if overhead is ₹50,000 and direct material cost is ₹2,00,000, rate = 25%. Each product absorbs overhead equal to 25% of its direct material cost. This method is simple and suitable when material cost dominates total cost and overhead varies with material usage. However, it fails when overhead is driven by labor or machine hours, not material value. It distorts costs for material-intensive products. Used in industries like furniture or packaging where material handling overhead correlates with material cost.
2. Direct Labor Cost Method
The overhead rate is expressed as a percentage of direct labor cost. Formula: (Budgeted Overhead / Budgeted Direct Labor Cost) × 100. If overhead is ₹60,000 and direct labor cost is ₹1,50,000, rate = 40%. Overhead absorbed = 40% of each product’s direct labor cost. This method works well when overhead varies with labor cost (e.g., supervision, welfare, overtime premiums). It is widely used in labor-intensive industries. However, it fails when different workers have different wage rates but consume similar overhead. Skilled workers with higher wages would absorb more overhead even if using same facilities as unskilled workers, causing cost distortion.
3. Direct Labor Hour Method
Overhead is absorbed based on actual direct labor hours worked on each product. Formula: Rate per labor hour = Budgeted Overhead / Budgeted Direct Labor Hours. If overhead is ₹1,00,000 for 20,000 labor hours, rate = ₹5 per hour. A product taking 10 hours absorbs ₹50 overhead. This method is more accurate than labor cost method because it ignores wage rate differences—a highly paid skilled worker and a low-paid helper each working one hour absorb same overhead if using same facilities. It is suitable where manual work dominates and overhead correlates with labor time. Used in assembly shops, repair workshops, and jobbing industries.
4. Machine Hour Rate Method
Overhead is absorbed based on machine hours used by each product. Formula: Rate per machine hour = (Total Overhead related to machines) / (Budgeted Machine Hours). Overhead includes depreciation, power, maintenance, lubricants, and machine insurance. For example, if machine-related overhead is ₹2,00,000 for 10,000 machine hours, rate = ₹20 per hour. A product requiring 5 machine hours absorbs ₹100 overhead. This is the most accurate method for machine-intensive industries like automotive, engineering, textiles, and plastics. It distinguishes between different machines by calculating separate rates for each machine or cost center. However, it ignores labor-intensive operations and requires detailed record-keeping.
5. Production Unit Method (Output Method)
Overhead is absorbed using a flat rate per unit of output produced. Formula: Rate per unit = Budgeted Overhead / Budgeted Number of Units. If overhead is ₹1,00,000 for 10,000 units, rate = ₹10 per unit. Each product passing through the cost center absorbs ₹10 overhead regardless of time or resources consumed. This is the simplest method but reliable only when a single homogeneous product is manufactured. It fails completely in multi-product situations where different products consume varying overhead resources. Used in foundries, brick kilns, cement plants, and sugar mills where identical units are mass-produced. No meaningful for job-order or batch production environments.
6. Prime Cost Percentage Method
Overhead is absorbed as a percentage of prime cost (direct material + direct labor + direct expenses). Formula: (Budgeted Overhead / Budgeted Prime Cost) × 100. If overhead is ₹80,000 and prime cost is ₹4,00,000, rate = 20%. A product with prime cost ₹500 absorbs ₹100 overhead. This method combines the effects of both material and labor, providing a broader base. It is simple and useful when overhead varies with both material and labor components. However, it assumes overhead is proportional to prime cost, which is rarely true. A product with high material cost but minimal processing time would absorb excessive overhead. Used only in small-scale or traditional costing systems.
7. Sales Price Method
Overhead is absorbed as a percentage of selling price or sales value of the product. Formula: (Budgeted Overhead / Budgeted Sales Value) × 100. If overhead is ₹1,20,000 and sales value is ₹6,00,000, rate = 20%. A product sold at ₹1,000 absorbs ₹200 overhead. This method is useful for pricing decisions when overhead recovery is linked to market value. However, it is logically flawed for cost determination because overhead causes cost, not selling price. Using sales price creates circular logic—high-priced products absorb more overhead regardless of actual resource consumption. This method is rarely used for internal costing but appears in some retail or distribution businesses.
Summary Table:
| Method | Absorption Base | Formula | Best Suited For |
|---|---|---|---|
| Direct Material Cost % | Direct material cost | (OH / Material) × 100 | Material-intensive, furniture |
| Direct Labor Cost % | Direct labor cost | (OH / Labor Cost) × 100 | Labor-intensive, small shops |
| Direct Labor Hour | Labor hours | OH / Labor Hours | Manual work, assembly |
| Machine Hour Rate | Machine hours | OH / Machine Hours | Machine-intensive, engineering |
| Production Unit | Units of output | OH / Units | Single homogeneous product |
| Prime Cost % | Prime cost | (OH / Prime Cost) × 100 | Small-scale, traditional |
| Sales Price % | Selling price | (OH / Sales) × 100 | Retail, distribution |
Under Absorption of Overheads
Under absorption (or under-recovery) of overheads occurs when the overheads charged to production (using predetermined absorption rates) are less than the actual overheads incurred during a period. This situation arises when actual activity level is lower than estimated, actual expenses exceed budgeted figures, or when there is inefficient utilization of resources. For example, if budgeted overhead is ₹1,00,000 for 10,000 machine hours (₹10 per hour), but actual overhead is ₹1,10,000 for 9,500 hours, absorbed overhead = ₹95,000 (9,500 × ₹10), resulting in under absorption of ₹15,000. Under absorption indicates that products have not borne their fair share of overheads, leading to understated product costs. It is adjusted at period end by debiting the under-absorbed amount to the costing profit and loss account.
Treatment of Under Absorption of Overheads:
1. Transfer to Costing Profit & Loss Account
The entire amount of under-absorbed overhead is transferred directly to the Costing Profit & Loss Account as a debit (additional expense). This method is simplest and most common when under-absorption is small or due to abnormal factors like machine breakdowns, power cuts, or idle capacity. It treats under-absorption as a period loss rather than adjusting product costs. For example, if under-absorption is ₹40,000, the Costing P&L Account is debited, reducing reported profit. However, product costs remain understated because they absorbed less overhead than actually incurred. This method is acceptable for internal reporting when adjustments are immaterial. Annual financial statements typically use this method after reconciliation with financial accounts.
2. Carry Forward to Next Period
The under-absorbed overhead is carried forward as a deferred debit (suspense account) to the next accounting period. This method is used when production is seasonal or cyclical, and overhead rates are designed to recover costs across periods. The under-absorbed amount appears as an asset (deferred cost) in the balance sheet. In the next period, it is adjusted against that period’s over-absorption or added to the predetermined rate. This treatment is common in industries with long production cycles (shipbuilding, construction). However, it violates accounting period concepts and is not accepted under GAAP/IFRS for external reporting. It is used only for internal cost management when fluctuations are temporary.
3. Adjustment by Supplementary Rate
The under-absorbed amount is adjusted by calculating a supplementary rate and charging it additionally to work-in-progress, finished goods, and cost of goods sold in proportion to their share of absorbed overhead. Formula: Supplementary Rate = (Under-absorption Amount / Total Absorbed Overhead) × 100. Each cost center’s product cost is increased by this percentage. This method is most accurate as it corrects actual production costs and inventory valuations. It is used when under-absorption is material and product costs must reflect true expenses for pricing or inventory valuation. Though detailed and time-consuming, standard costing systems prefer this method at year-end for financial reporting compliance.
4. Write-Off to Cost of Goods Sold (COGS)
The under-absorbed overhead is added entirely to the Cost of Goods Sold (COGS) account. This treatment assumes that most of the period’s production has been sold, making inventory adjustment unnecessary. It is simpler than the supplementary rate method but less accurate when significant work-in-progress or finished goods inventory exists. For example, if COGS is ₹5,00,000 and under-absorption is ₹40,000, adjusted COGS becomes ₹5,40,000, reducing gross profit. This method is acceptable under marginal costing but not under absorption costing for external reporting. Cost accountants use it for monthly or quarterly statements when inventory levels are stable. At year-end, full supplementary adjustment is preferred.
Methods of Under Absorption:
1. Actual Overhead Exceeds Budgeted Overhead
Under absorption occurs when actual overhead expenses are higher than the budgeted or estimated overhead used to set the predetermined absorption rate. For example, if budgeted factory rent was ₹1,00,000 but actual rent paid is ₹1,20,000 (due to rent escalation), the predetermined rate based on ₹1,00,000 will be insufficient. Consequently, for the same activity level, the overhead recovered will be less than the actual expense incurred. This shortfall is under absorption. Causes include unexpected inflation in indirect material prices, unplanned repair costs, or regulatory increases in property taxes. Cost accountants must investigate such variances and consider updating budget estimates more frequently to minimize this cause.
2. Actual Activity Level Below Budget/Estimated Level
Under absorption arises when the actual production volume or activity base (e.g., labor hours, machine hours) is lower than the level used to set the predetermined absorption rate. Since the rate is fixed as (Budgeted Overhead / Budgeted Activity), operating below budgeted activity reduces the total overhead recovered. For instance, if the budget was 10,000 machine hours but actual is only 8,000 hours, the firm recovers overhead for only 8,000 hours, leaving a portion of fixed overhead unrecovered. This is the most common cause of under absorption, especially during demand downturns. It highlights the risk of using predetermined rates based on optimistic or historical activity levels. Seasonal industries frequently face this issue.
3. Inefficiency or Idle Time
Operational inefficiencies leading to excessive idle time (machine breakdowns, power failures, material shortages, worker absenteeism) cause under absorption. During idle time, overheads continue to accrue (e.g., rent, supervisor salary, depreciation), but no production occurs to absorb them through the predetermined rate. The actual hours worked fall short of the budgeted productive hours, reducing the recovery base. For example, if machines remain idle for 200 hours due to maintenance delays, overhead that should have been absorbed during those 200 hours remains unrecovered. This under absorption signals poor production planning or maintenance policies. Management must analyze idle time reports and take corrective action to improve capacity utilization.
4. Errors in Setting Predetermined Rates
Under absorption results from faulty estimation of either budgeted overhead or budgeted activity level while setting the predetermined absorption rate overestimates activity or underestimates overhead. For example, if a cost accountant assumes 20,000 machine hours based on unrealistic production targets, but achievable hours are only 15,000, the rate (Overhead / 20,000 hours) will be too low. Even with perfect execution, actual hours at 15,000 will yield less recovery than actual overhead, assuming overhead was correctly budgeted. This cause is administrative and avoidable through better forecasting techniques, historical data analysis, and incorporating learning curves. Annual rate reviews and flexed budgets help detect such estimation errors early.
