Restaurant Finance
Prime cost combines two of the largest controllable operating costs in most restaurants: cost of goods sold and labor. It is useful because it forces the owner to look at purchasing, production and staffing together instead of managing them in separate silos.
Prime cost formula
Prime cost = Cost of goods sold + Labor cost
To express it as a percentage of sales:
Prime cost % = Prime cost ÷ Net sales × 100
The exact components included in labor and cost of goods sold should be defined consistently with your accounting method. Do not compare one period with another if the definitions change.
Why operators track prime cost
Food cost can look acceptable while labor is too high, or labor can look efficient while waste and purchasing are deteriorating. Prime cost brings both sides together so management can see whether operating margin pressure is coming from product cost, labor cost or both.
Build the number from reliable inputs
- Use a consistent sales period.
- Use a reliable inventory value for cost of goods sold.
- Capture direct labor costs consistently.
- Document whether payroll taxes, benefits or other labor-related costs are included.
- Do not mix cash purchases or unposted invoices into different periods without adjustment.
For food-cost controls, read How to Control Food Cost in a Small Restaurant. For labor, see Restaurant Labor Cost Control Made Simple.
Use weekly prime cost as an operating signal
A weekly estimate can be more actionable than waiting for month-end accounts. It will not replace formal accounting, but it can help management react earlier to purchasing spikes, weak sales, overtime or schedule drift.
Diagnose the drivers before cutting
A high prime-cost result is not an instruction to cut staff or reduce portions automatically. Diagnose the cause. Sales may have dropped unexpectedly, a supplier price may have jumped, overtime may have increased because of training, or inventory counts may be wrong.
Questions to ask in the weekly review
- Did sales volume or sales mix change?
- Were there unusual supplier purchases?
- Did recipe prices change?
- Was labor scheduled to expected demand?
- Was overtime planned or accidental?
- Did waste or rework increase?
- Are inventory counts reliable?
Do not manage to a universal number
Different concepts have different labor models, ingredient mixes, service levels and price structures. Use external benchmarks carefully. Your own budget, concept economics and historical trend are often more useful than a generic target applied without context.
Manager takeaway
Prime cost is most useful when reviewed as a trend with clear operating definitions—not as a single target copied from another restaurant.