Edible Portion (EP) Cost Calculator

Why the invoice price is the wrong number for costing

You buy weight and you sell portions, and the two are never the same weight. A case of bone-in pork shoulder at $2.40 a pound arrives with bone, sinew and a fat cap that you will not serve. Whatever survives the knife then goes into an oven and loses more to evaporation and rendered fat. The price you paid still has to be recovered from the food that reaches the plate, so the true cost of that food is higher than the invoice — sometimes by a little, often by half again.

Edible portion cost is that adjusted figure: the invoice price divided by the trim yield. It is the number a costing sheet should carry for any item you fabricate. Divide once more by the cooking yield and you get the cost of a pound as it is actually served, which is the number a portion cost should be built from when you portion after cooking.

The correction is not cosmetic. At a 75% yield and a 20% cooking loss — the values this calculator loads with — the cost per served pound is 1.67 times the invoice price. Cost that item at the invoice price and every plate containing it is understated by 40% of its true ingredient cost, on a sheet whose arithmetic is otherwise perfect.

Two divisions, in order, and why they are never multiplications

EP cost = AP cost ÷ trim yield. If 75% of the case is usable, the money you spent is spread over 75% of the weight, so each usable pound carries 1 ÷ 0.75 = 1.333 times the invoice price. The instinct to add the 25% loss is wrong and always understates: adding gives 1.25, dividing gives 1.333.

Served cost = EP cost ÷ (1 − cooking loss). The same logic on the second loss. A 20% cooking loss means a pound of trimmed raw product becomes 0.8 lb of cooked food, so cooked food costs 1 ÷ 0.8 = 1.25 times the EP cost.

The two yields multiply, they do not add. A 75% trim yield followed by a 20% cooking loss delivers 0.75 × 0.80 = 60% of the purchase weight to the plate, so the combined premium is 1 ÷ 0.60 = 1.667. Adding the losses (25% + 20% = 45%, implying a 55% survival) would give 1.818 and over-cost the dish. Order matters conceptually: the trim yield applies to what the supplier delivered, and the cooking loss applies to what came off your bench.

Portion cost = served cost × portion oz ÷ 16, because there are sixteen ounces in a pound. Enter the portion as it is plated. If you portion raw — a 7 oz raw steak that plates at 5.5 oz — then set the cooking loss to zero here and use the raw portion weight, because you are buying and portioning the same state of the product.

Where does the trim yield come from? A yield test. Weigh a case in, break it down, weigh what is usable, divide. The food yield percentage calculator runs that test and produces exactly the percentage this calculator consumes.

How to read the premium, and what to do with it

The premium output is the single most useful figure here, because it is the size of the error you would have made using the invoice price. Below about 20% the invoice price is a rough working number for a quick estimate. Between 20% and 50% it is materially wrong. Above 50% — bone-in cuts, whole fish, artichokes, anything sold with tops — quoting the purchase price at all is misleading.

The premium also settles buying decisions that price lists cannot. Compare like for like on cost per usable pound, never on price per pound. Whole tenderloin at $18.00 with a 70% yield costs $25.71 per usable pound; a trimmed centre-cut at $24.50 with no waste costs $24.50. The convenience product wins on food cost before you have counted a single minute of butchery labour. Reverse the yields and the answer reverses too — the point is that the comparison is impossible without this conversion.

Two adjustments make the picture honest. First, credit valuable by-products: if bones make stock you would otherwise buy, or fat renders into something you use, that value offsets the trim. Second, count the labour. Butchery time is real payroll, and it lands in the same prime cost as the food does — the restaurant prime cost calculator is where that trade-off actually gets settled, because in-house fabrication moves cost from one line to the other rather than removing it.

Cost multipliers for combined trim and cooking loss

Read the worked example off this table: 75% trim yield and 20% cooking loss gives 1.667, and $6.00 × 1.667 = $10.00 per served pound.

Assumptions this calculation makes

• The yield is yours, not a book's. Published yields vary with specification, season and knife skills. Run a test and replace the default.
• Trim has no value. If bones, fat or offcuts genuinely earn their keep, subtract that value from the run cost separately.
• Labour is excluded. Fabricating in house shifts cost from food to payroll; this calculator only sees one of those.
• Cooking loss is measured against raw trimmed weight. A figure quoted against the as-purchased weight will double-count the trim.
• Portion control is assumed perfect. Real over-portioning shows up in your actual food cost, not on this sheet.
• Prices are a snapshot. Recost when the invoice price moves, and re-test the yield when the specification does.

Where EP cost sits in the costing chain

Edible portion cost is the translation layer between purchasing and the menu. Upstream, a yield test measures how much of a case survives fabrication; the food yield percentage calculator produces that percentage and the ordering multiplier that goes with it. Downstream, the adjusted price is what belongs on every line of a costing sheet: enter EP costs rather than invoice prices in the recipe cost per serving calculator and your plate costs stop flattering the trimmed items on your menu.

For events, the same two yields run in the opposite direction to turn a headcount into an order — that is what the catering food quantity per person calculator does, using the identical ÷ cooking yield ÷ trim yield chain applied to weight instead of money.

Use a different approach where the losses are not weight losses at all. Bakers track absorption and bake loss against flour weight rather than yield percentages; bar programmes cost by the pour against a bottle's usable volume, where the equivalent of trim is spillage and free pour; and portion-cut, individually quick-frozen and canned items need no conversion at all, because their yield is effectively 100%. The rule of thumb is simple: if you throw part of it away or cook weight out of it, convert the price before you cost the dish.

Key terms

AP cost

As-purchased cost: the price per pound or kilogram on the invoice, covering every part of the product including what you will discard.

EP cost

Edible portion cost: AP cost divided by the trim yield, giving the price of a pound of usable, trimmed, raw product.

Cooking yield

One minus the cooking loss. A 20% loss is an 80% cooking yield, and the two multiply with trim yield rather than adding.

Cost premium

How much higher the served cost is than the invoice price, expressed as a percentage. It equals 1 ÷ (trim yield × cooking yield) − 1.