What belongs in the prime cost calculation?
Use a consistent definition for each period. Food-and-beverage cost should reflect inventory used, while labor includes the relevant wages, salaries and employer costs. Restaurant365 explains these components and the inventory formula: opening inventory plus purchases minus closing inventory.
Prime cost is an operating measure, not the restaurant’s final profit. Rent, utilities and other business expenses still need to be considered. For this guide, all values are fictional US-dollar amounts for one week, and the sales figure excludes sales tax. Keep your own accounting classifications consistent when preparing actual reports.
Worked example: calculate one complete restaurant week
Start with the supporting records before typing a percentage. In this example, beginning inventory is $6,400, purchases are $12,100 and ending inventory is $5,100. Inventory used is therefore $6,400 + $12,100 − $5,100 = $13,400.
| Measure | Amount | Share of sales |
|---|---|---|
| Sales | $42,000 | 100.00% |
| Food and beverage COGS | $13,400 | 31.90% |
| Hourly wages | $10,500 | 25.00% |
| Allocated salaried labor | $2,300 | 5.48% |
| Employer taxes and benefits | $1,900 | 4.52% |
| Total labor | $14,700 | 35.00% |
| Prime cost | $28,100 | 66.90% |
The calculation is ($13,400 + $14,700) ÷ $42,000 × 100 = 66.90%. The $13,900 remaining after these two cost categories must still cover the other business expenses; label it “sales less prime cost,” not net profit.
Why using purchases alone changes the answer
The kitchen used $1,300 more inventory than it bought during this example week. Entering only the $12,100 of purchases would produce prime cost of $26,800 and a ratio of 63.81%. That understates the illustrated result by about 3.10 percentage points.
Write the inventory count date beside each value. A delivery received after the closing count belongs in the next consistent period. If a count or invoice is missing, mark the report provisional and list what needs checking. A calculated percentage with incomplete inputs should not look as final as a reconciled one.
Build a weekly prime cost spreadsheet you can audit
Use one row per week and keep the source references alongside the numbers. An illustrative layout uses B for sales, C for opening inventory, D for purchases, E for closing inventory, F for hourly wages, G for allocated salaries and H for employer costs.
- COGS in I2:
=C2+D2-E2 - Total labor in J2:
=SUM(F2:H2) - Prime cost in K2:
=I2+J2 - Prime cost ratio in L2:
=IF(B2>0,K2/B2,""), formatted as a percentage.
Flag zero or missing sales separately rather than interpreting the blank ratio as 0%. These references describe this teaching example; they do not promise a particular layout in a SheetChief product. Retain the original inventory, sales and payroll records so another person can reproduce the row.
Separate a spending change from a sales change
Keep the same $28,100 prime cost but change sales to $39,000. The ratio becomes 72.05%. Prime cost dollars have not changed, yet the ratio rises by about 5.15 percentage points because the sales base is smaller.
Record all three movements when comparing weeks: COGS dollars, labor dollars and sales dollars. Then check the operating context. A closure, an event or a different number of trading days can make two weeks hard to compare. The percentage shows what happened mathematically; it does not, by itself, identify waste or poor scheduling.
Use a target as a question to investigate
Suppose this fictional operator sets a 65% target. At $42,000 sales, the corresponding allowance is $27,300, so the example is $800 above that target. The 65% figure is an input for this scenario, not a universal recommendation.
Investigate a specific cause before acting: verify a supplier price change, reconcile a count difference or compare scheduled hours with actual hours. Save a short note naming the issue, the supporting record and the next review date. That note makes the following week’s comparison more useful than repeatedly coloring a cell red.
Connect prime cost to the rest of your restaurant records
For the ingredient side, use the recipe cost per serving guide. For the distinction between ingredient percentages and profit, read food cost percentage versus profit margin.
SheetChief sells the linked digital tools. The Restaurant Profit & Loss Spreadsheet with Prime Cost Dashboard, Staff Schedule & Labor Cost Planner and Restaurant Inventory Spreadsheet cover related recordkeeping tasks. Review their current Etsy previews and included features to choose the appropriate tool.
Put this into practice
Restaurant Spreadsheet Templates for Google Sheets & Excel · Try the free calculator
Compare the actual product previews and included files before choosing a paid template.
Sources and further reading
The explanations and worked examples are prepared for SheetChief. These sources support the referenced methods or platform instructions.
Questions, answered
What is the restaurant prime cost percentage formula?
Add cost of goods sold to total labor cost, divide by sales from the same period, then multiply by 100. A spreadsheet ratio can instead be formatted as a percentage.
Are purchases the same as food cost?
Not necessarily. In the simple inventory calculation, cost used equals opening inventory plus purchases minus closing inventory. A stock increase or decrease makes purchases differ from usage.
Can prime cost rise as a percentage without spending more?
Yes. If prime cost dollars stay unchanged while sales fall, the percentage rises. Compare the amounts as well as the ratio.
Is sales minus prime cost my net profit?
No. The remaining amount still needs to cover business expenses not included in COGS and labor.
Related SheetChief tools
These are our own products. The examples above explain the task; check each Etsy listing to confirm which features and formats are included.
