What Is the Food Cost Formula?

The food cost formula is how you take "we spent this much on food" and turn it into something you can actually compare week to week. It looks like this:

Food Cost Percentage: Cost of Goods Sold ÷ Total Food Sales × 100

The part people get stuck on is Cost of Goods Sold, or COGS. It isn't what you bought from vendors; it's what you actually went through. You get there by taking your inventory at the start, adding what came in, then subtracting whatever's still sitting on the shelf at the end.

Beginning Inventory + Purchases − Ending Inventory = COGS

Say your walk-in and storage held $10,000 worth of product on Monday. You bought another $5,000 over the week. By the following Monday, $8,000 was left. That means you went through $7,000 worth of food. If sales for that stretch came to $20,000, your food cost lands at 35 percent.

Why bother with all this instead of just glancing at invoices? Because purchases by themselves lie a little. Stock up heavily one week and barely touch it, and that week looks way worse than it actually was. Backing out what's left corrects for that.

Owners who run this number regularly, not once a year at tax time, are the ones who catch trouble early. A supplier raising prices, portions drifting, spoilage piling up quietly in the back, this formula tends to flag it before it shows up anywhere else on the books.