Direct Costs

Every business needs to know what its products, jobs or customers cost, and the answer has two parts. Some costs belong unambiguously to one product: the steel in a particular chair, the hours a joiner spent making it, the fabric bought for it.

These can be measured and charged to the chair directly, with no allocation or estimate. Other costs are incurred for the whole factory: the rent, the supervisor's salary, the electricity, the depreciation of shared machinery.

These benefit every chair and belong to none in particular, and they can only be charged to a chair by an allocation rule. The first group are direct costs, the second indirect, and the line between them is drawn by whether the cost can be traced to the object without an allocation.

Direct costs are conventionally split into three. Direct materials are the materials that become part of the product or are consumed specifically in making it, measured by the quantities used at their purchase cost.

Direct labour is the pay of the people who work on the product, measured by the time spent at their loaded hourly rate. Direct expenses are other costs incurred specifically for the product or job: subcontracted work, hire of special equipment, royalties or licence fees per unit, design work for a specific order, and freight on a specific delivery.

The sum of the three is the prime cost. Adding a share of production overhead gives the full production cost; adding selling and administrative overhead gives the total cost.

Which costs are direct depends on the cost object, and the same cost can be direct for one object and indirect for another. A production supervisor's salary is indirect to any single product but direct to the production department; a sales manager's salary is indirect to a product but direct to the region; the rent of a factory that makes one product is direct to that product.

Tracing also has to be economical: the glue on a chair is technically traceable but too small to be worth measuring, so it is treated as indirect. Decisions about what to trace are made with the cost of tracing in mind, and modern systems, which capture time and materials by job automatically, have made more costs direct than was once practical.

The distinction drives decisions in several ways. In pricing, the direct cost is the floor below which a sale loses money on its own terms, and the margin above direct cost is what covers overheads and produces profit; a business that prices on direct cost alone will be busy and unprofitable, while one that loads every quote with full overhead will lose work that would have contributed.

In contract and project accounting, direct costs are what customers can be billed for on cost-plus terms and what auditors test. In profitability analysis, direct costs by customer or product are reliable, and the overhead allocation on top is where the argument lies.

And in short-term decisions such as accepting a special order, making or buying a component, or dropping a product, the relevant costs are usually the direct costs that would change, not the allocated overhead that would not. Direct cost is not the same as variable cost, though the two overlap.

Direct materials are both direct and variable; a machine hired for one job is direct but fixed for the duration; factory power is variable but indirect. Direct describes traceability; variable describes behaviour with volume.

Both distinctions are useful and they answer different questions: direct cost answers "what does this product cost us specifically?", variable cost answers "what would change if we made one more?".