How to Calculate Food Cost % and Plate Cost (With a Worked Example)

In every kitchen I have run, the first number on the whiteboard was food cost. Not revenue, not covers — food cost. It tells you, before the month is over, whether the menu is making money or quietly losing it. This article walks through the method I teach young chefs, with a complete worked example you can copy.

What food cost percentage actually measures

Food cost percentage is the share of a dish's selling price that goes to the ingredients on the plate:

Food cost % = ingredient cost per plate ÷ selling price × 100

If a plate costs you 4.20 in ingredients and sells for 14.00, the food cost is 30%. The remaining 70% is your gross margin — the money left to pay staff, rent, energy, waste and, finally, profit.

Most professional kitchens aim for 25–35%. The right target depends on your concept: a fine-dining tasting menu can live with a higher food cost because the ticket is large; a high-volume café needs to stay tighter because every other cost is spread over small tickets.

Step 1 — Cost the whole batch, not the portion

Chefs rarely cook one portion at a time, and suppliers never sell one portion at a time. So start with the batch.

For each ingredient line, write down three things:

• How much you use in the batch (800 g of chicken thigh).
• What you pay, and for how much (22.00 for 1 kg).
• The unit on both sides — this is where most mistakes hide.

The line cost is then:

Line cost = (quantity used ÷ purchase quantity) × purchase price

Chicken thigh: (0.8 kg ÷ 1 kg) × 22.00 = 17.60 for the batch.

Do the same for every line. Convert units honestly: 60 ml of olive oil bought by the litre is 0.06 of the bottle. Count items (onions, eggs) are costed per piece from the pack price.

Don't forget yield

A whole fish, a bunch of herbs or a head of celery is not 100% usable. If you keep 70% of a product after trimming, divide the line cost by 0.70. Ignoring yield is the most common reason a kitchen "can't understand" why real food cost is five points above the theoretical figure.

Step 2 — Divide by portions to get the plate cost

Add the lines up for the batch, then divide by the number of plates the batch produces.

Four portions → plate cost 5.83.

Step 3 — Price for a target, not from a guess

Instead of asking "what should this cost?", ask "what price gives me the food cost I want?":

Target price = plate cost ÷ (target food cost % ÷ 100)

At a 30% target: 5.83 ÷ 0.30 = 19.42. Round to the menu psychology you use (19.50, 19.90) and check it against what the market will accept. If the market price is lower, the dish needs a cheaper build or a smaller protein portion — the maths tells you that before the first guest orders it.

Step 4 — Compare theoretical and actual

The plate cost above is theoretical: it assumes every gram goes where the recipe says. Your actual food cost comes from purchases and stock counts:

Actual food cost % = (opening stock + purchases − closing stock) ÷ food sales × 100

The gap between theoretical and actual is waste, over-portioning, theft, spoilage and un-recorded staff meals. A 2–3 point gap is normal; a 6-point gap is a project.

Common mistakes I still see

• Costing a dish once and never again while supplier prices drift.
• Mixing units (grams used, kilos bought) and getting a number ten times too small.
• Forgetting garnish, sauces and bread — the "free" items on the plate.
• Using the menu price including tax as the selling price.

Do it in a minute instead of an hour

You can run the whole calculation above with the free plate cost calculator and the food cost calculator — no account needed. Inside AKROUN FOOD AI, every recipe is costed automatically from your own inventory prices, so the food cost column updates itself when a supplier price changes.

Know your number. Everything else in the kitchen gets easier once you do.