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Full absorption cost per unit includes direct materials, direct labor and allocated variable and fixed production overhead. Follow a machine-hour allocation, reconcile inventory to production cost and keep unallocated idle-capacity cost separate.
Full absorption cost per unit combines direct materials, direct labor and allocated factory overhead, then divides by the production units those costs belong to. Include both variable and fixed production overhead. Keep unallocated idle-capacity costs separate so unusually low output does not inflate the inventory cost of each unit.
Full absorption cost per unit = (Direct materials + Direct labor + Allocated variable production overhead + Allocated fixed production overhead) / Production units
Fixed overhead allocation rate = Fixed production overhead pool / Normal production activity
Overhead allocated to a product = Applicable overhead rate × Product's allocation activity
The activity can be machine hours, direct labor hours or another documented production driver. Separate overhead pools may be needed when different activities cause different costs. A unit count works when the products consume the resources in sufficiently similar proportions.
OpenStax explains absorption costing as assigning direct costs and both variable and fixed manufacturing overhead to products. Its distinction from variable costing is the treatment of fixed manufacturing overhead.
Full absorption does not mean every company expense belongs in inventory. Keep selling and general corporate costs outside the production pool. The broader cost of goods sold explanation covers the expense recognized when inventory is sold; this calculation establishes the cost assigned to each produced unit first.
Use a production register with product, order, completion date, completed quantity and activity consumed. The cost export needs ledger row, account, factory cost center, period and amount. Material issues and labor records should identify the order or product whenever they are directly traceable.
The overhead schedule needs another field: the allocation rule approved for each pool. Retain its normal-capacity denominator, rate and effective period. Without that schedule, a difference between plants may come from allocation policy rather than operating performance.
The IRS inventory guidance identifies direct materials, direct labor and certain indirect costs as manufactured inventory cost elements. That is tax guidance, with capitalization rules of its own; it should not replace the controller's financial reporting policy or normal-capacity assessment.
Keep opening and closing work in process available too. The following example has neither. If production remains unfinished, first assign costs between completed goods and work in process; cost per equivalent unit addresses that processing-stage calculation.
A Wisconsin manufacturer produces standard and reinforced brackets during September 2026. It completes every order in the month. Normal activity and actual activity are both 6,000 machine hours, so this example has no capacity shortfall or overhead allocation variance.
The overhead export contains variable production overhead of $36,000 and fixed production overhead of $84,000. The production and direct cost exports contain:
| Product | Completed units | Machine hours | Direct materials (USD) | Direct labor (USD) |
|---|---|---|---|---|
| Standard bracket | 4,000 | 2,000 | 120,000 | 60,000 |
| Reinforced bracket | 2,000 | 4,000 | 40,000 | 30,000 |
| Total | 6,000 | 6,000 | 160,000 | 90,000 |
First calculate the overhead rates. Money is shown to two decimal places when expressed per hour or per unit; all calculations below are exact before that display rounding.
| Overhead rate | Calculation | Rate (USD per machine hour) |
|---|---|---|
| Variable | 36,000 / 6,000 actual machine hours | 6.00 |
| Fixed | 84,000 / 6,000 normal machine hours | 14.00 |
| Combined in this example | 6.00 + 14.00 | 20.00 |
| Product | Calculation | Allocated overhead (USD) |
|---|---|---|
| Standard | 2,000 × 20.00 | 40,000 |
| Reinforced | 4,000 × 20.00 | 80,000 |
Then add direct costs and divide by completed units:
| Product | Direct costs (USD) | Allocated overhead (USD) | Full production cost (USD) | Full absorption cost per unit (USD) |
|---|---|---|---|---|
| Standard | 120,000 + 60,000 = 180,000 | 40,000 | 220,000 | 220,000 / 4,000 = 55.00 |
| Reinforced | 40,000 + 30,000 = 70,000 | 80,000 | 150,000 | 150,000 / 2,000 = 75.00 |
| Total | 250,000 | 120,000 | 370,000 |
The reinforced bracket has lower material cost per unit but consumes more machine time. An equal overhead charge per finished bracket would hide that difference.
The allocation check is $40,000 + $80,000 = $120,000, matching $36,000 + $84,000 in the overhead export. The production cost check is $160,000 materials + $90,000 labor + $120,000 overhead = $370,000.
You can also rebuild each unit cost from its components:
| Component per unit | Standard (USD) | Reinforced (USD) |
|---|---|---|
| Direct materials | 120,000 / 4,000 = 30.00 | 40,000 / 2,000 = 20.00 |
| Direct labor | 60,000 / 4,000 = 15.00 | 30,000 / 2,000 = 15.00 |
| Variable overhead | 2,000 × 6.00 / 4,000 = 3.00 | 4,000 × 6.00 / 2,000 = 12.00 |
| Fixed overhead | 2,000 × 14.00 / 4,000 = 7.00 | 4,000 × 14.00 / 2,000 = 28.00 |
| Full unit cost | 55.00 | 75.00 |
If the company sells 3,000 standard and 1,500 reinforced brackets, the remainder stays in finished goods. There is no opening finished inventory in this illustration.
| Product | Units sold | COGS (USD) | Ending units | Ending inventory (USD) |
|---|---|---|---|---|
| Standard | 3,000 | 3,000 × 55.00 = 165,000 | 1,000 | 1,000 × 55.00 = 55,000 |
| Reinforced | 1,500 | 1,500 × 75.00 = 112,500 | 500 | 500 × 75.00 = 37,500 |
| Total | 4,500 | 277,500 | 1,500 | 92,500 |
COGS of $277,500 plus ending inventory of $92,500 equals the $370,000 assigned to production. That reconciliation proves where the production cost went; the sales ledger alone cannot prove it.
Suppose the same fixed overhead pool remains $84,000, but actual production activity falls unusually low, to 3,000 machine hours. Retain the normal-capacity basis of 6,000 hours in this illustration:
| Fixed overhead reconciliation | Calculation | Amount (USD) |
|---|---|---|
| Fixed overhead allocated | 3,000 hours × 14.00 | 42,000 |
| Unallocated fixed overhead | 84,000 - 42,000 | 42,000 |
| Actual fixed overhead pool | 42,000 + 42,000 | 84,000 |
Under this illustrated allocation policy, the unallocated $42,000 is a period expense rather than additional unit inventory cost. Keep abnormal waste and other excluded costs identifiable as well. Have finance confirm the normal-capacity estimate, treatment of unusually high output and any spending or allocation variances before using the schedule for financial statements.
An actual spending comparison may still show total factory cost divided by actual output. Label it clearly: average manufacturing cost per unit can answer an operating question while the inventory allocation answers a financial reporting question.
Bring your production register, cost export and overhead allocation schedule to Covirage. Covirage maps the columns, and its tools compute and check supplied allocation rates, product costs and reconciliations; the external AI model explains the result with every figure traced to its rows. Create a free Covirage account and bring a sample of your own data.
See cost variance analysis for the supporting finance context.
Full absorption product cost includes manufacturing costs. Sales commissions, advertising and general corporate expenses normally remain period expenses. A separate pricing analysis may consider those costs, but adding them changes the measure and should be clearly labeled.
Absorption costing assigns allocated fixed manufacturing overhead to products along with variable manufacturing costs. Variable costing treats fixed factory overhead as a period expense. The distinction affects when fixed cost reaches earnings if production and sales quantities differ.
An equal amount per unit is reasonable only when units consume the shared production resources similarly. Products with different machine time, setup work or labor demands need an allocation basis that reflects those differences. Keep the chosen basis consistent and documented.
Use the normal-capacity basis to identify the fixed overhead allocated to production and show the unallocated amount separately as a period expense. Do not make each unit absorb all actual fixed spending simply because an unusually small number of units was produced.