HOS-CULI27-07 · Lesson 6 · 10.5 clock hours · theory
Portion Control, Yield, and Plate Cost Math
Objective. Students will calculate as-purchased cost, edible-portion cost, and per-plate cost for a three-item entrée using yield percentages and current market prices, achieving results within 5% of instructor's verified answer.
⚠ Pending professional review
This lesson, its worked examples and its practice questions has not yet been verified by a certified food-safety manager and industry professional or by a certification or approval body. It is a study draft and may contain errors. Do not use it as instructions for work on a job site or on live equipment. Always follow your instructor, your supervising professional, and current official references and regulations.
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Why Plate Cost Math Matters
Every dish you plate carries a price tag that the kitchen controls. A beautifully composed entrée loses money the moment the cost exceeds the selling price your restaurant has budgeted. Chefs who understand portion control, yield percentages, and plate cost math protect the operation's profitability while maintaining consistent quality for every guest. These skills also connect directly to ACF Certified Culinarian competencies, which expect you to apply basic food-cost principles in a professional kitchen.
As-Purchased Cost vs. Edible-Portion Cost
When you buy a whole beef tenderloin, you pay for the entire piece — fat, silverskin, chain, and all. That total price divided by total weight is the as-purchased (AP) cost per unit. After you trim the tenderloin, the weight you can actually serve is smaller. That trimmed, usable weight gives you the edible portion (EP). Because you paid for more than you can serve, every ounce of edible product costs more than the AP price suggests. Ignoring this gap leads to systematic underpricing and real financial losses.
AP Cost per lb = Total purchase price ÷ Total pounds purchased
Once you know AP cost and your yield percentage, you convert:
EP Cost per lb = AP Cost per lb ÷ Yield %
Always express yield percentage as a decimal (e.g., 75% = 0.75) when performing division.
Calculating Yield Percentage
Yield percentage tells you what fraction of the as-purchased weight becomes usable food.
Yield % = Edible-Portion Weight ÷ As-Purchased Weight × 100
Example: A 5-lb beef tenderloin is trimmed and yields 3.6 lb of usable meat. Yield % = (3.6 ÷ 5.0) × 100 = 72%.
Yield percentages vary by product and by trimming skill. Standard culinary references (such as the On Cooking food-costing appendix or the USDA) publish average yields for common proteins, produce, and grains, but always weigh your actual trim in a working kitchen — your supplier's quality and your own knife work affect the real number.
Cost per Edible Ounce
Plate portions in the United States are typically expressed in ounces, so it is useful to convert EP cost per pound to EP cost per ounce:
EP Cost per oz = EP Cost per lb ÷ 16
This gives you the cost of each ounce of usable product and lets you price any portion size quickly.
Per-Plate Cost for a Multi-Component Entrée
A composed entrée has multiple components — protein, starch, vegetable, sauce, and garnish. Calculate the EP cost for each component at its plated portion weight, then add them together:
Plate Cost = Σ (EP Cost per oz × Portion oz) for each component
For items sold by the pound at purchase (most proteins and vegetables), work through AP → Yield % → EP Cost per lb → EP Cost per oz → Portion cost. For pre-portioned or processed items with no trim loss, AP cost equals EP cost and yield % = 100%.
Portion Control on the Line
Precise portioning is the bridge between the math and the plate. A digital scale accurate to 0.1 oz is the standard tool. Eyeballing portions introduces inconsistency that compounds across dozens of covers and erodes the cost calculations you worked out in advance. Use portion scoops, ladles, and ring molds for starches and sides; weigh proteins every time until muscle memory is verified by scale.
Key practice: tare the scale with the plate or container in place, then weigh the food net. Never estimate.
Safety Points for This Lesson
Although this is a theory lesson focused on math, the worked example involves handling butchered proteins and a digital scale in a lab environment. Observe these points whenever you handle raw proteins or demonstrate yield work:
- Cross-contamination prevention: Keep raw proteins on designated cutting boards (color-coded per your kitchen's system). Never place raw protein on a surface used for ready-to-eat food without sanitizing first — this is a core ServSafe principle.
- Temperature control: Raw proteins used in demonstration must be kept at or below 41°F until the moment of use and returned to refrigeration promptly. Bacteria multiply rapidly in the temperature danger zone (41°F–135°F).
- Scale hygiene: Sanitize the scale platform before and after placing raw protein on it. A food-safe sanitizing solution at the correct concentration is required.
- Hand hygiene: Wash hands thoroughly after handling raw protein. Do not touch calculation forms, calculators, or shared materials with contaminated hands.
Connecting to Food Cost Percentage
Operators typically track overall food cost percentage — total food cost divided by total revenue — and set a target (commonly in the 28–35% range for full-service restaurants, though targets vary widely by concept). Your plate cost math feeds directly into this metric. If your plate costs $6.20 and the menu price is $22.00, food cost % = $6.20 ÷ $22.00 = 28.2%. Knowing this number lets leadership price menus responsibly and adjust purchasing when costs rise.
Summary
To price a plate accurately: (1) find AP cost per lb from your invoice, (2) weigh actual usable yield and calculate yield %, (3) divide AP cost by yield % to get EP cost per lb, (4) convert to EP cost per oz, (5) multiply by each component's portion weight, and (6) sum all components. Use a digital scale, show all work, and re-check arithmetic — a 5% error in a high-volume kitchen translates to real dollars lost or overcharged.
Key terms8
As-Purchased (AP) CostThe price paid for a food item at its original purchase weight, before any trimming, fabrication, or cooking loss is removed.
Edible-Portion (EP) CostThe cost of a food item calculated on its usable, trimmed weight; always higher than AP cost when trim loss exists.
Yield PercentageThe ratio of edible-portion weight to as-purchased weight, expressed as a percentage; calculated as (EP weight ÷ AP weight) × 100.
Portion ControlThe practice of measuring each serving to a predetermined weight or volume to ensure consistency in quality and cost.
Plate CostThe total edible-portion cost of all components in a single plated dish; found by summing the EP cost of each ingredient at its portioned weight.
Food Cost PercentageTotal food cost expressed as a percentage of food revenue; used by operators to evaluate profitability and set menu prices.
Tare WeightThe weight of an empty container or plate that is zeroed out on a scale so that only the food weight is measured.
Temperature Danger ZoneThe temperature range between 41°F and 135°F in which bacteria that cause foodborne illness multiply most rapidly; raw proteins must be kept out of this range except during active cooking or service.
Worked examples4
1. A 5-lb beef tenderloin is purchased for $9.60 per lb. After trimming, the usable yield is 3.6 lb. (a) What is the yield percentage? (b) What is the EP cost per lb? (c) What is the EP cost per oz?
- AP cost per lb = $9.60 (given).
- Yield % = (EP weight ÷ AP weight) × 100 = (3.6 ÷ 5.0) × 100 = 72%.
- EP cost per lb = AP cost per lb ÷ yield % (as decimal) = $9.60 ÷ 0.72 = $13.33 per lb.
- EP cost per oz = EP cost per lb ÷ 16 = $13.33 ÷ 16 = $0.833 per oz, rounded to $0.83 per oz.
Answer: Yield % = 72%; EP cost per lb = $13.33; EP cost per oz = $0.83.
2. Using the beef tenderloin from the previous example (EP cost = $0.83 per oz), a plate also includes a 5-oz portion of roasted fingerling potatoes (AP $1.20/lb, yield 90%) and a 3-oz portion of haricots verts (AP $2.40/lb, yield 85%). Calculate the plate cost for one entrée with a 6-oz beef portion.
- Beef: EP cost per oz = $0.83 (from previous example). Portion = 6 oz. Beef cost = 6 × $0.83 = $4.98.
- Potatoes: EP cost per lb = $1.20 ÷ 0.90 = $1.333 per lb. EP cost per oz = $1.333 ÷ 16 = $0.0833 per oz. Portion = 5 oz. Potato cost = 5 × $0.0833 = $0.42.
- Haricots verts: EP cost per lb = $2.40 ÷ 0.85 = $2.824 per lb. EP cost per oz = $2.824 ÷ 16 = $0.1765 per oz. Portion = 3 oz. Vegetable cost = 3 × $0.1765 = $0.53.
- Plate cost = $4.98 + $0.42 + $0.53 = $5.93.
Answer: Plate cost = $5.93.
3. A 10-lb bag of russet potatoes costs $6.50. After peeling and trimming, the edible yield is 7.8 lb. (a) What is the yield percentage? (b) A recipe calls for a 4-oz portion of mashed potatoes per plate. What is the ingredient cost of the potato component per plate?
- AP cost per lb = $6.50 ÷ 10 = $0.65 per lb.
- Yield % = (7.8 ÷ 10.0) × 100 = 78%.
- EP cost per lb = $0.65 ÷ 0.78 = $0.8333 per lb.
- EP cost per oz = $0.8333 ÷ 16 = $0.0521 per oz.
- Cost for 4-oz portion = 4 × $0.0521 = $0.21.
Answer: Yield % = 78%; potato cost per 4-oz portion = $0.21.
4. A restaurant sells a salmon entrée for $28.00. The total plate cost (protein + starch + vegetable + sauce) is $8.40. What is the food cost percentage, and does it fall within a typical 28–35% target range?
- Food cost % = (Plate cost ÷ Menu price) × 100.
- Food cost % = ($8.40 ÷ $28.00) × 100 = 30%.
- 30% falls within the commonly cited 28–35% target range for full-service restaurants.
Answer: Food cost percentage = 30%; this falls within a typical target range.
The math in this lesson2
Learners compute a 72% tenderloin yield and divide $9.60 AP cost for $13.33 EP per pound.
7.RP.3N-Q.1
In class: Instructor-led worked example on whiteboard: butcher a 5-lb beef tenderloin, weigh trim and usable yield, calculate yield percentage, then compute cost per edible ounce and per plate at a stated portion weight. · Students complete three independent yield-and-cost problems using provided market price sheets for protein, starch, and vegetable components; work shown on structured calculation forms. · Peer review: student pairs exchange completed forms, verify arithmetic, and flag discrepancies; instructor resolves disputes with class; students correct and resubmit.
Materials: Scales (digital, 0.1-oz resolution), butchered yield example proteins (pre-trimmed), market price sheets, portion-cost calculation forms, calculators, On Cooking appendix on food costing
Check: Three-problem calculation worksheet graded by instructor; all three final plate-cost figures must fall within 5% of verified answer; students who miss must redo with a parallel problem set before advancing to Lesson 7.
Practice check8
Answer each question, then check it. Nothing is recorded; this is your own practice.
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