§ 17

Portion price with loss (conversion factor)

What does meat or fish cost in one finished portion when I calculate loss?

Answer: You pay for the product you buy, but the guest gets only what is left after cleaning, deboning and preparation. The conversion factor tells you how many kg you should buy to get 1 kg finished product. The calculator uses your purchase price, your waste percentage and the portion's finished weight to find the raw material price per portion, the price per kg finished product and the total purchase. You must measure the waste percentage yourself or find it in the kitchen's calculation sheet.

Formula

Omregningstal = 1 ÷ (1 − svind % ÷ 100). Ved 30 % svind er det 1 ÷ 0,7 ≈ 1,43

Indkøb pr. portion = færdig portion × omregningstal

Råvarepris pr. portion = indkøb pr. portion (kg) × indkøbspris pr. kg

Pris pr. kg færdig vare = indkøbspris × omregningstal

Symbols and units in the formula
Symbol	Meaning	Unit
kilopris	Purchase price per kg (gross, excl. VAT)	kr/kg
svind_pct	Total loss (cleaning + preparation)	%
netto_g	Finished portion (net on plate)	g
portioner	Number of portions	portioner
=	Ingredient cost per portion	kr
=	Conversion factor (kg purchase per kg finished product)	×
=	Purchase per serving (gross)	g
=	Total purchase	kg
=	Price per kg finished product	kr/kg

Validity and source

Source: Calculation · competence objective 'shrinkage percentage and conversion factors to set prices and convert recipes'

Does not apply when

Loss must cover everything that does not end up on the plate: trimming, bones, skin and weight loss in frying or cooking. Measure it by weighing before and after using your own method. Price is raw material only. Wages, energy and other costs are outside.

Worked example

The calculator's own default values inserted. The figures are calculated with exactly the formula the tool uses.

Substituted

Purchase price per kg (gross, excl. VAT)79 kr/kg
Total loss (cleaning + preparation)30 %
Finished portion (net on plate)160 g
Number of portions90 portioner

Giver

Ingredient cost per portion18.06 kr
Conversion factor (kg purchase per kg finished product)1.43 ×
Purchase per serving (gross)229 g
Total purchase20.6 kg
Price per kg finished product112.86 kr/kg

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Sådan bruger du den

Når du kalkulerer en ret, skal råvareprisen dække det, du køber, og ikke kun det, gæsten får. Omregningstallet fortæller, hvor mange kg du skal købe for at få 1 kg færdig vare. Beregneren bruger indkøbspris, svind og portionens færdige vægt til at give prisen pr. portion og det samlede indkøb.

Step by step

Find indkøbsprisen pr. kg uden moms på fakturaen.
Mål svindet: vej varen ved indkøb og igen, når den er renset og tilberedt.
Regn omregningstallet: 1 ÷ (1 − svind ÷ 100).
Gang portionens færdige vægt med omregningstallet. Det er indkøbet pr. portion.
Gang indkøbet i kg med kiloprisen. Det er råvareprisen pr. portion.

Typical errors

At regne prisen ud fra fakturaens kilopris alene. Ved 45 % svind er den rigtige pris næsten dobbelt så høj.
At gange med (1 + svind) i stedet for at dele med (1 − svind). Ved 30 % giver det 1,30 i stedet for 1,43.
At måle svindet på én god dag. Mål over flere leverancer, så tallet holder.

Examples from everyday life

Flæskesteg til julefrokost

Svinekam med svær koster 79 kr pr. kg. Stegning og udskæring giver 30 % svind. Hver gæst skal have 160 g færdig steg, og der er 90 gæster.

Purchase price per kg (gross, excl. VAT): 79 kr/kg
Total loss (cleaning + preparation): 30 %
Finished portion (net on plate): 160 g
Number of portions: 90 portioner

It means: Stegen koster 18.06 kr pr. portion. Omregningstallet er 1.43 ×, så hver portion kræver 229 g rå kam, og du skal bestille 20.6 kg. Prisen pr. kg færdig steg er 112.86 kr/kg.

Laks på à la carte-kortet

Hel laks koster 95 kr pr. kg. Filetering, skind og afpuds giver 45 % svind. Portionen er 140 g filet, og du regner med 40 portioner i weekenden.

Purchase price per kg (gross, excl. VAT): 95 kr/kg
Total loss (cleaning + preparation): 45 %
Finished portion (net on plate): 140 g
Number of portions: 40 portioner

It means: Laksen koster 24.18 kr pr. portion. Omregningstallet er 1.82 ×, så hver portion kræver 255 g hel fisk. Til 40 portioner skal du købe 10.2 kg. Ren filet koster dig 172.73 kr/kg.

Rule of thumb

Ved 30 % svind koster færdig vare ca. 1,4 gange kiloprisen. Ved 50 % svind koster den det dobbelte.

How to check the answer

Indkøbet pr. portion ganget med (1 − svind) skal give portionens færdige vægt. Prisen pr. kg færdig vare ganget med portionens kg skal give prisen pr. portion.