Job Costing vs Process Costing: Key Differences Explained
Job costing tracks the unique cost of each custom project—like a tailor pricing a bespoke suit—while process costing averages the cost of identical, mass-produced units—like a bakery pricing every loaf in a batch.
People mix them up because both methods tally materials, labor, and overhead. A project-based firm might use job costing for a custom app but switch to process costing for routine software patches, blurring the line.
Key Differences
Job costing assigns costs to individual jobs, ideal for low-volume, high-variation work. Process costing accumulates costs by department or process, perfect for high-volume, uniform output. One focuses on uniqueness; the other on averages.
Which One Should You Choose?
Pick job costing when every unit is different—construction, legal cases, custom design. Choose process costing for continuous, identical production—oil refining, bottled water. Hybrid setups are common in modern ERPs.
Examples and Daily Life
A wedding planner uses job costing for each couple’s unique package, while a coffee chain uses process costing for every cup poured during the morning rush. Both live in the same QuickBooks file.
Can a company use both methods?
Yes. A furniture maker might track custom tables with job costing and mass-produced chairs with process costing, splitting the factory floor accordingly.
Does process costing ignore individual defects?
No. Defect rates are averaged into the cost per unit, but severe defects are still flagged and investigated separately to protect margins.