Meaning
Distribution of indirect manufacturing costs that do not vary with production volume across the units produced during a period. This process assigns expenses like factory rent, insurance, property taxes and equipment depreciation to the individual products held in inventory. While the total cost remains constant, fixed overhead allocation causes the unit cost to fluctuate based on how many items the factory completes.
Capacity Basis
Standard cost systems use a predetermined rate calculated at the start of the year. This rate for fixed overhead allocation is usually based on normal capacity, which represents the expected volume of production over several periods. Using this baseline ensures that product costs remain stable even if seasonal demand shifts temporarily.
Volume Variance
Differences between actual production and the planned capacity result in a financial variance. If the plant produces fewer units than expected, the fixed overhead allocation fails to absorb the full amount of the actual costs. This under absorption appears as a negative variance on the income statement.
Conversely, producing more units than the normal capacity level leads to over absorption, which lowers the cost of goods sold and increases the reported margin for that specific period.
Operational Efficiency
Monitoring these rates helps management understand the true cost of idle capacity. A high fixed overhead allocation per unit often signals that the facility is too large for its current market share. These insights drive decisions about facility consolidation or equipment upgrades.