What Is Yield Percentage — and Why Is Your Real Cost per Kilo Higher?

Yield percentage is the share of a product that's actually usable after trimming, peeling, filleting, or cooking. A whole sea bass at 50% yield gives you 500 g of servable fish per kilo purchased — which means your real cost per kilo is double the invoice price. The formula: yield % = (usable weight ÷ purchased weight) × 100.

Every chef knows this instinctively. Far fewer put it in their costings — and that gap is where menus quietly lose money.

AP vs EP: the two prices of every ingredient

The trade terms:

• AP — As Purchased. What the invoice says. €30/kg for the whole fish.
• EP — Edible Portion. What ends up on the plate. The fillets, after head, bones, skin, and trim.

The number that belongs in your recipe costing is always EP cost:

EP cost per kg = AP price per kg ÷ yield %

That sea bass: €30 ÷ 0.50 = €60 per usable kilo. If your costing says €30, every dish with that fish is lying to you by half.

Real yield numbers from a working kitchen

Yields vary with product quality, size, and the hands doing the work — but these are honest starting points:

Two lessons hide in that table. First, the expensive products often have the worst yields — fish and specialty produce punish invoice-price costing hardest. Second, no table replaces your own numbers: weigh a real delivery once — whole product on the scale, usable product on the scale, divide. Ten minutes per key ingredient, and your costings stop guessing.

Cooking loss: the second yield

Trimming is only the first shrink. Roasting, braising, and grilling take another cut — a beef roast can lose 20–30% of its weight in the oven. For dishes portioned after cooking, chain the yields:

True cost per served kg = AP price ÷ (trim yield × cooking yield)

A €18/kg beef cut at 80% trim yield and 75% cooking yield really costs €18 ÷ (0.80 × 0.75) = €30 per served kilo. That's the number your portion cost must be built on.

Where yield thinking changes decisions

• Buying whole vs. prepped. Pre-cut fillets at €55/kg against whole fish at €30/kg with 50% yield: the fillets are cheaper (€55 vs €60 EP) — before you count the labor of filleting. Yield math turns "obviously buy whole" into an actual calculation. (The trim has value too — stocks, sauces — if you truly use it. Be honest about whether you do.)
• Supplier comparison. A cheaper supplier whose product trims worse can be the more expensive one. Compare EP costs, never AP.
• Portion pricing. Every portion on the menu should trace back to an EP cost. If it traces to an invoice price, the food-cost percentage on that dish is fiction.

Related questions

Is yield the same as waste percentage? They're mirror images: yield 60% = waste 40%. Kitchens track whichever they act on — yield for costing, waste for reduction targets.

Do I need to re-measure yields often? When the product changes: new supplier, different size grade, seasonal shift. A winter carrot and a spring bunch carrot don't trim the same.

Does yield apply to liquids? Yes — reductions are extreme yields. A jus reduced 10:1 makes each liter served carry the cost of ten.

What's an acceptable yield? There's no universal target — only a known one. The failure isn't a 45% fish yield; it's costing the fish as if it were 100%.

Catalin Cucu is a chef and the founder of DigitalKnife — the kitchen toolkit that costs plates, tracks yields, and keeps the math honest.