What Is COGS in a Restaurant? (And Why It Matters)

COGS stands for Cost of Goods Sold. In a restaurant, it represents the total cost of food and beverage ingredients you used to generate revenue over a specific period. Not what you bought, but what you actually used.

It directly determines your gross profit, yet many operators calculate it wrong, too infrequently, or not at all.

The COGS Formula for Restaurants

COGS = Beginning Inventory + Purchases - Ending Inventory

Example for one week:

• Beginning inventory (Monday morning): $12,000
• Purchases received (Monday through Sunday): $8,500
• Ending inventory (Sunday night): $10,500

COGS = $12,000 + $8,500 - $10,500 = $10,000

That $10,000 is the value of ingredients consumed during the week. If food revenue was $33,000, your food cost percentage would be:

($10,000 / $33,000) x 100 = 30.3%

Why "Purchases" Is Not the Same as COGS

This is the most common mistake. Vendor invoices tell you what you bought, not what you used. If you bought $10,000 but $2,000 is still in the walk-in, actual cost of goods used was $8,000.

This is why you need inventory counts. Without beginning and ending inventory values, you cannot calculate true COGS. You are just tracking spending.

Actual vs. Theoretical COGS

Actual COGS

What we calculated above. Based on real inventory counts and purchases. Tells you what you actually used.

Theoretical COGS

What you should have used based on sales mix and recipes. If you sold 100 lattes at $0.60 in ingredients each, theoretical latte cost is $60.

Calculate it by multiplying the ingredient cost of each menu item by units sold, then summing across all items.

The Variance

Variance = Actual COGS - Theoretical COGS

If actual is $10,000 and theoretical is $8,500, you have a $1,500 variance, about 15% waste.

Sources of variance:

• Over-portioning: More on the plate than the recipe calls for
• Waste: Spoilage, trim waste, dropped or burned product
• Theft
• Unrecorded sales: Comps, staff meals, and samples not tracked
• Recipe inaccuracy: Recipes do not reflect how the dish is actually made

The variance does not tell you the cause, but it tells you the magnitude and where to investigate.

Using COGS to Make Better Decisions

Menu pricing

A popular dish with 42% food cost? Raise the price, reduce the portion, or find a cheaper substitute. Knowing your plate cost per item lets you decide with data.

Vendor negotiation

When you know exactly what you spend per ingredient category, you negotiate from knowledge. "I spend $3,200/month on dairy across three vendors. What can you do if I consolidate?"

Portion control

Comparing actual vs. theoretical by category pinpoints over-portioning. If protein variance is 20% but dry goods is 3%, you know where to focus training.

Ordering decisions

Accurate COGS reveals usage patterns. Consistently using 18 cases of chicken per week? Negotiate a standing order instead of ad-hoc purchases at retail pricing.

Identifying theft

A sudden spike in COGS for specific items (especially high-value proteins or alcohol) without a corresponding sales increase is a red flag.

Why Monthly COGS Is Not Enough

Most operators track COGS monthly, when their bookkeeper reconciles. A monthly number is too stale to act on.

If food cost spiked in week one because a new cook was over-portioning, you will not know until four weeks later. Three more weeks of lost margin.

Weekly COGS gives a much tighter feedback loop. You spot problems within days and correct before they compound.

The tradeoff has always been time. Weekly counts, weekly data entry, weekly calculations. Most operators settle for monthly because the weekly process is too burdensome.

Making COGS Tracking Practical

A typical weekly COGS calculation requires:

1. Counting all inventory (1.5-3 hours)
2. Entering counts into a spreadsheet (30-60 minutes)
3. Gathering purchase invoices (20-30 minutes)
4. Running calculations (10-20 minutes)
5. Analyzing results (15-30 minutes)

That is 3-5 hours per week. For a small operation where the owner is also on the line, that time does not exist.

Stockcount compresses this. Voice counting cuts inventory to under an hour. Purchase data flows in from invoice scanning. COGS, both actual and theoretical, calculates automatically in real time.

Instead of a number from your accountant once a month, you get a live dashboard that updates every time you count or log a purchase. When food cost drifts, you know this week, not next month.

Try Stockcount free for 14 days and see what real-time COGS tracking looks like.