How to work out what one portion costs

Setting a menu price by "whatever the competition charges" is a common method. The trouble with it: there is a good chance the competition did exactly the same. Somewhere along that chain, somebody has to have done the arithmetic.

A price set without knowing what one portion costs you is a guess. Guesses sometimes land; when they do not, there is no way to see where it went wrong.

The calculation in three steps

1. The unit price of the ingredient. Divide what you paid by how much you got. If 1 kg of flour costs 45 ₺, that is 0.045 ₺ a gram. If the recipe uses 200 grams of flour, that line costs 9 ₺.

2. The recipe total. Convert every ingredient the same way and add them up. A recipe is rarely one portion — you need an answer to "how many portions does this pot make".

3. The cost per portion. Divide the recipe total by the number of portions it makes.

That is the easy part.

The waste allowance — the line everyone skips

If the recipe says 1 kg of potatoes, the kitchen does not go through 1 kg of potatoes. There are peelings, there is spoilage, there is cooking loss.

A cost that ignores waste comes out below the truth and makes the price look safer than it is. The result is insidious: the numbers look fine, the till does not add up.

The surest way to measure your waste allowance is to weigh for a week. The difference between the raw weight you buy and the weight that reaches the plate is your waste rate. A percentage taken off the internet works as a starting point, but it is not your kitchen's number.

What the food cost percentage tells you

The food cost percentage shows how much of the selling price goes on ingredients:

food cost percentage = cost per portion ÷ selling price

The band commonly used in restaurants is 25–35%. But that is an industry habit, not a mathematical rule. If you are somewhere with high rent the same percentage may not be enough for you; for someone working out of a home kitchen it may even be generous.

What actually earns its keep is not the percentage itself but seeing the difference between products. If one item on the menu sits at 20% and another at 48%, the second one is carrying the business on your back.

When prices rise

Ingredient prices do not go up together. One doubles while another stays still. In a kitchen that never costs its recipes, it takes months to notice which dish has slipped into a loss — the takings keep turning over but no money is left.

Recalculating the cost of your best sellers a few times a year is far cheaper than overhauling the menu from scratch.

To do the calculation

We wrote the food cost calculator for exactly this. You enter the ingredients, the purchase prices and how many portions the recipe makes, then add the waste allowance as a percentage. Enter a selling price too and it shows the food cost percentage and the profit per portion.

No sign-up, no account. The prices you type never leave your browser — nothing is sent to any server.

One step further

Knowing the cost per portion is the first step. The second is knowing how much you sell. Until those two sit side by side, menu decisions still rest on guesswork.

Our QR menu and ordering system records how many of each item went out and takes stock down by the unit — grams, millilitres or pieces. The whole ordering flow is open on the free tier; I went into the detail in this article.