Use two inventory counts and what you bought in between to get your real food cost percentage.
Food cost % = (beginning inventory + purchases − ending inventory) ÷ food sales × 100. Count at the same time each week so every period is the same length. Most restaurants aim for 28–35%.
The Restaurant Inventory & Food Cost Tracker does this and much more in Google Sheets and Excel: saved, organized and protected so nothing breaks. Buy once, $16.
See the Restaurant Inventory & Food Cost Tracker