What it means
Overhead covers everything a factory spends that cannot be traced to a single unit: supervision, factory rates, machine depreciation, cleaning, quality checks and consumables. Accounting standards require these production costs to sit in the value of stock rather than being expensed as incurred, so some method of attaching them to units is unavoidable.
In the bookkeeping, applied overhead is added to work in progress while actual overhead collects in a separate control account. At the end of the period the two are compared, and any difference is disposed of rather than left dangling.
Two things cause that difference, and separating them is where the management insight lies. A spending difference means the factory simply spent more or less than budgeted, while a volume difference means the plant ran more or fewer hours than the rate assumed, so fixed costs were spread over a different number of units.
Disposal of the difference is not just tidying up. Writing an underapplied balance straight to cost of sales lowers reported profit immediately, whereas spreading it across closing stock and cost of sales moves part of the charge into next period, which is why auditors care when the amount is material.
The rate itself deserves an annual argument rather than a copy-paste. A rate built on an optimistic sales forecast produces a low charge per hour, understates product cost all year, and then delivers an unpleasant surprise in the final month when reality is reconciled.
In practice
Real-world examples.
Example
A craft brewery applies overhead at $12 per machine hour. In a month using 2,500 machine hours it applies 2,500 x $12 = $30,000, but the actual bills total $32,400, so the month is underapplied by $32,400 - $30,000 = $2,400 and the plant manager is asked to explain the gap.
Example
A bespoke furniture maker applies overhead at 150% of direct labour cost. A dining table order with $4,000 of direct labour carries $4,000 x 1.5 = $6,000 of applied overhead, giving a conversion cost of $4,000 + $6,000 = $10,000 before materials.
Example
A contract electronics assembler expands its plant mid-year without changing its rate, and finishes $180,000 underapplied. The whole balance is written off to cost of sales in December, cutting reported gross profit by $180,000 in a single month and prompting an awkward conversation with the bank.
Formula
Calculation
Predetermined overhead rate = budgeted overhead / budgeted activity
Applied overhead = predetermined overhead rate x actual activity
Over or under applied = applied overhead - actual overhead incurred
A furniture factory budgets $1,200,000 of production overhead and 40,000 direct labour hours, giving a rate of $1,200,000 / 40,000 = $30 per direct labour hour. The plant is busier than expected and records 42,000 direct labour hours, so applied overhead is 42,000 x $30 = $1,260,000.
Actual overhead for the year turns out to be $1,215,000. Because $1,260,000 - $1,215,000 = $45,000, overhead is overapplied by $45,000, meaning products have been charged $45,000 more than the factory really spent, and that credit must be removed from cost of sales and stock before the accounts are published.Case study
Seen in the real world.
This is a fictional illustration. Redgrave Cycles, an invented frame manufacturer, set its rate from a budget of $1,000,000 of overhead and 40,000 direct labour hours, giving $1,000,000 / 40,000 = $25 per hour. A strong year pushed actual hours to 44,000, so applied overhead reached 44,000 x $25 = $1,100,000 while actual overhead was only $1,040,000, leaving $1,100,000 - $1,040,000 = $60,000 overapplied.
The management accountant's first instinct was to credit the whole $60,000 to cost of sales, which would have added $60,000 to reported profit. The auditors pointed out that 30% of the year's output was still sitting in finished goods, and that stock was carrying its share of the overcharge.
Splitting the balance in proportion gave $60,000 x 0.30 = $18,000 against closing stock and $60,000 x 0.70 = $42,000 against cost of sales. Reported profit rose by $42,000 rather than $60,000, and the fictional company's closing inventory value fell by $18,000 to something closer to what the goods had genuinely cost.
Watch out
Common mistakes.
- Assuming applied overhead is wrong whenever it differs from actual overhead, when a difference is expected and only its size and cause matter.
- Rolling last year's rate forward without checking whether the cost base or the expected activity level has changed.
- Dumping a large underapplied balance entirely into cost of sales when a material part of the year's output is still in stock, which understates inventory on the balance sheet.
Questions
People also ask.
Does applied overhead include selling and administrative costs?
No, only production overhead is applied to goods, because accounting standards keep selling and administrative costs out of the value of stock and charge them in the period they occur.
Why not simply wait and use the actual overhead figure?
Because decisions on pricing, stock valuation and monthly reporting cannot wait months for every invoice to land, and a rate fixed in advance keeps unit costs comparable across the year.
What does a persistently underapplied balance signal?
Usually that the plant is running below the activity level built into the rate, that costs have risen since the budget, or both, and it is a prompt to reset the rate rather than to keep absorbing the shortfall.
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