Enter your opening stock, purchases and closing stock value for each category, plus your sales for the period and target cost percentage. The tool calculates your actual cost of goods used, compares it to what you'd expect at target, and shows the value and percentage of any wastage or loss.
| Category | Opening Stock | Purchases | Closing Stock | Usage |
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Usage = Opening Stock + Purchases − Closing Stock. This is the actual value of stock consumed during the period — through sales, wastage, spoilage, staff meals or theft — regardless of the reason.
Your expected cost of sales is what usage should be if every item sold matched its costed recipe exactly: Total Sales × Target Cost %. Comparing this to your actual usage reveals the gap — your variance.
Common causes include over-portioning, over-pouring at the bar, spoilage from poor stock rotation, kitchen waste and trimming beyond the costed allowance, staff meals not recorded, comps and discounts not accounted for, and — in some cases — theft. A consistently high variance points to a process issue worth investigating rather than a one-off.
Your target cost % should come from your actual recipe costings (see the Food Cost and Drink Cost calculators), not an arbitrary industry figure. A well-run kitchen or bar should be able to hold actual cost within 1–2 percentage points of target on a rolling basis.
Weekly stocktaking of high-value or high-risk categories (spirits, meat, fish) combined with a full monthly stocktake gives good early warning of variance without the operational burden of counting everything daily.
This calculator provides estimates based on the figures you enter. It does not identify the cause of any variance — further investigation of your specific operation is required. JWBIZ Ltd accepts no liability for stock or financial decisions made on the basis of this tool.