Quick answer
Yield is the share of a raw ingredient that actually reaches the plate after trimming, cleaning and cooking; everything else is waste you still paid for. If you build food cost on the invoice price instead of the edible-portion cost per kg, you understate a dish by 15–40% on the trickier products. The key formula is: edible-portion cost per kg = purchase price ÷ yield as a decimal. Measure the real yield of your products and re-cost the recipes.
What yield is and why it's a hidden cost
When you buy a case of spinach, a whole sea bass or a veal leg, you pay for the gross weight. But the kitchen doesn't use all of it: you discard stems, bones, fat, skin, peel and bruised parts. What stays usable is the yield.
The catch is that yield never shows up on the invoice. The supplier sells you 1 kg, you pay for 1 kg, but maybe 600 grams make it onto the plate. You paid for those 400 grams of waste all the same: it's a real cost hiding inside every recipe. Anyone who ignores it works with a theoretical food cost lower than reality, and only notices at month end, staring at margins that don't add up.
Yield is expressed as a percentage or a decimal. A 70% yield means 1 kg gross delivers 0.7 kg net. The lower the yield, the higher the real cost of the ingredient compared with its purchase price.
The edible-portion cost formula
There's only one formula to memorise:
Edible-portion cost per kg = Purchase price per kg ÷ Yield (as a decimal)
A concrete example. You buy beef tenderloin at €28/kg. After removing fat, silverskin and portioning offcuts, the yield is 75% (0.75).
Edible-portion cost = 28 ÷ 0.75 = €37.33/kg
Almost €10 per kilo of difference. If you cost your tournedos at €28/kg instead of €37.33, you understate the portion cost by about 33%. On a 160 g net portion that's 0.160 × 37.33 = €5.97 of real cost versus the €4.48 you'd have booked using the gross price — roughly €1.50 vanishing on a single dish.
To stay safe, always run the invoice price through the yield before bringing it into the food cost calculator. The ingredient yield calculator automates exactly this step.
Indicative yield table by category
Yields vary by product, season, quality and the hands doing the prep, but these ranges give you a starting point. Always measure your own numbers: the table is for estimating, not for replacing the scale.
| Raw ingredient | Trim yield | Yield after cooking | Notes | |---|---|---|---| | Beef tenderloin | 70–80% | 65–70% | More offcuts on small pieces | | Whole sea bass | 40–50% | 35–45% | Filleting: head, bones, skin | | Whole salmon | 55–65% | 50–55% | Higher yield than sea bass | | Chicken breast | 90–95% | 70–75% | Steep loss when cooked | | Artichokes | 30–40% | — | Among the lowest of all | | Fresh spinach | 60–70% | 15–20% cooked | Huge drop with cooking | | Potatoes | 80–85% | 80% | High and stable yield | | Tomatoes for sauce | 60–70% | 30–40% reduced | Evaporation counts | | Onions | 85–90% | — | Only skin and ends | | Whole prawns | 45–55% | 40–45% | Head and shell weigh in |
Note the two columns: for many products you must apply two yields in sequence. Fresh spinach yields 60–70% after cleaning, but in the pan it collapses to 15–20% of the original gross weight. If you serve sautéed spinach and cost it on the cleaned raw weight, you're wrong again.
Trimming and cooking: two different yields
Keep the two stages separate, because they hit differently depending on the dish:
- Trim (or prep) yield: what's left after removing inedible or unused parts. Always relevant, on any prepped product.
- Cooking yield: what's left after moisture loss during cooking. Relevant when the portion you serve is cooked and you weigh it cooked (e.g. roast by cooked weight, braises, reductions).
For a carpaccio only trim yield matters. For a braised cheek both matter, because the cheek loses fat and water and the final cooked portion is much lighter than the raw. The formula chains:
Total yield = Trim yield × Cooking yield
Example: a cheek with 90% trim yield and 65% cooking yield → total yield = 0.90 × 0.65 = 0.585, i.e. 58.5%. From 1 kg of raw cheek you get 585 g of servable braise.
How to measure real yield (a 4-step test)
Don't trust generic tables. Run a quick test on the 10–15 ingredients that weigh most on your food cost:
- Weigh the gross on arrival, before touching it (e.g. 2,000 g of whole sea bass).
- Prep it the way you always do and weigh the usable net (e.g. 880 g of fillets).
- Calculate the yield: net ÷ gross = 880 ÷ 2,000 = 0.44 → 44%.
- If served cooked, also weigh after cooking and multiply the two yields.
Repeat on 3–5 samples of the same product and average them: a single reading can mislead because of piece size or who's doing the cleaning. Record the average yield on the ingredient spec sheet and update it whenever you change supplier or season.
Full example: from gross to selling price
Let's put it all together on a roasted sea bass dish with a 160 g net raw portion.
| Item | Value | |---|---| | Whole sea bass price | €18.00/kg | | Filleting yield | 44% (0.44) | | Edible-portion cost per kg | 18 ÷ 0.44 = €40.91/kg | | Net raw portion | 160 g | | Ingredient cost per portion | 0.160 × 40.91 = €6.55 |
Had you used the invoice price (€18/kg) you'd have booked 0.160 × 18 = €2.88 — less than half the true cost. With a 30% target food cost, the correct selling price for the base ingredient alone is 6.55 ÷ 0.30 ≈ €21.80, versus the €9.60 you'd have put on the menu by getting it wrong. That's the gap between making money and running at a loss without knowing it.
Always carry the edible-portion cost into the food cost calculation to close the loop.
Common mistakes
- Using the invoice price in food cost. The number-one error. On whole fish, artichokes, spinach and bone-in meat you're off by 15–40%.
- Forgetting cooking yield. For roasts, braises and reductions the cooking loss is huge; ignoring it skews the cooked portion.
- Using a single measurement. A yield should be averaged over several samples: one unlucky piece or a rushed cook distorts the figure.
- Not updating yields. They shift with season, supplier and quality. Artichoke yield in early and late season is not the same.
- Throwing away noble trim. Carcasses, bones, peels and offcuts become stocks, broths, powders and bases. Recovered waste is recovered food cost and less rubbish.
- Not weighing the waste. If you don't know how much you bin, you don't know how much you pay for nothing. A week of weighing scraps is often worth more than months of price negotiations.
Yield and sustainability: two sides of the same coin
Improving yield isn't only about margin. Every gram of waste avoided or recovered is food that doesn't hit the bin, weight you don't pay for twice (at the till and at disposal) and reduced environmental impact. Choosing higher-yield cuts, recovering noble trim and sizing portions to true yield brings down both food cost and your kitchen's footprint. Here, sustainability and the P&L pull in the same direction.
Related resources
- Ingredient yield calculator — enter the gross price and yield, get the edible-portion cost per kg instantly.
- Food cost calculator — bring the edible-portion cost into the calculation for accurate food cost and selling price.