Prime cost is

Prime cost is the total of all direct costs incurred in manufacturing a product. It includes only those costs that can be traced directly to production units - specifically direct materials consumed and direct wages (direct labour). Factory overheads, indirect wages, depreciation of plant, and other indirect manufacturing expenses are excluded from prime cost because they are indirect costs.

The formula is:

\[ \text{Prime Cost} = \text{Direct Materials Consumed} + \text{Direct Wages} \]

where:

\[ \text{Direct Materials Consumed} = \text{Opening Stock of Raw Materials} + \text{Purchases of Raw Materials} + \text{Carriage Inwards (if any)} - \text{Closing Stock of Raw Materials} \]

Applying this formula to the data provided in the table, the prime cost works out to #49,950.

A common mistake is to include factory overheads (such as factory rent, power, depreciation of machinery, or indirect wages) in the prime cost. These items are part of factory cost (also called production cost or works cost), not prime cost. Factory cost = Prime cost + Factory overheads. Including any overhead figure would overstate the prime cost and lead to an incorrect, higher total such as #53,000 or #52,750.

Another error is miscalculating direct materials consumed by omitting the stock adjustment. If opening or closing stock of raw materials is ignored, the materials figure will be wrong, producing a distorted prime cost.

Exam tip: When a question asks for prime cost, include only direct materials consumed and direct wages. Stop there. Do not add any item described as "overhead", "indirect", "factory rent", "depreciation", or "factory expenses".