Explanation

Overhead variances arise when the actual overhead costs incurred differ from the expected amounts. Managers want to understand the reasons for these differences, and so should consider computing one or more of the overhead variances described below. Each of these variances applies to a different aspect of overhead expenditures. It is not necessary to calculate these variances when a manager cannot influence their outcome.

Fixed Overhead Spending Variance

The fixed overhead spending variance is the difference between the actual fixed overhead expense incurred and the budgeted fixed overhead expense. An unfavorable variance means that actual fixed overhead expenses were greater than anticipated. The formula for this variance is:

Actual fixed overhead - Budgeted fixed overhead = Fixed overhead spending variance

The amount of expense related to fixed overhead should (as the name implies) be relatively fixed, and so the fixed overhead spending variance should not theoretically vary much from the budget.

Fixed Overhead Volume Variance

The fixed overhead volume variance is the difference between the amount of fixed overhead actually applied to produced goods based on production volume, and the amount that was budgeted to be applied to produced goods. For example, a company budgets for the allocation of $25,000 of fixed overhead costs to produced goods at the rate of $50 per unit produced, with the expectation that 500 units will be produced. However, the actual number of units produced is 600, so a total of $30,000 of fixed overhead costs are allocated. This creates a fixed overhead volume variance of $5,000.

Variable Overhead Efficiency Variance

The variable overhead efficiency variance is the difference between the actual and budgeted hours worked, which are then applied to the standard variable overhead rate per hour. The formula is:

Standard overhead rate x (Actual hours - Standard hours)

= Variable overhead efficiency variance

A favorable variance means that the actual hours worked were less than the budgeted hours, resulting in the application of the standard overhead rate across fewer hours, resulting in less expense being incurred. However, a favorable variance does not necessarily mean that a company has incurred less actual overhead, it simply means that there was an improvement in the allocation base what was used to apply overhead.

Variable Overhead Spending Variance

The variable overhead spending variance is the difference between the actual and budgeted rates of spending on variable overhead. The variance is used to focus attention on those overhead costs that vary from expectations. The formula is:

Actual hours worked x (Actual overhead rate - standard overhead rate)

= Variable overhead spending variance

A favorable variance means that the actual variable overhead expenses incurred per labor hour were less than expected.

In the study guide, CIPS splits overhead variance into volume and expenditure variance. They can be understood as variable and fixed overhead variance respectively.