Trim waste and loss
Waste factor
The number you multiply the clean quantity by to know how much to buy as purchased.
Try it in the calculatorWhat it is and why it matters
The waste factor is the number you multiply a clean quantity by to know how much to buy as purchased. It also turns an as-purchased price into its equivalent clean price.
It's best to work it out from the trim waste %, because you'll need that percentage for many other calculations.
The formula
- Factor = trim waste % ÷ (100 − trim waste %) + 1
- Same as: Factor = 100 ÷ (100 − trim waste %)
- Another way: Factor = gross weight ÷ net weight
What each value means
- Trim waste %
- How much of the purchased product is lost when cleaning it.
- 100 − trim waste %
- The usable part: what is left clean from every 100 you buy.
- Waste factor
- How many times more you must buy as purchased compared with what you need clean.
Step by step
- Take the trim waste % of the raw material.
- Work out the usable part: 100 − trim waste %.
- Divide the trim waste % by the usable part.
- Add 1.
Worked examples
Whole salmon
Whole salmon has 25% trim waste (head, bones and skin), so 75% is usable.
Factor = 25 ÷ 75 + 1 = 0.3333 + 1 = 1.333.
For every kilo of clean fillet you need, you have to buy 1.333 kg of whole salmon.
Study notes
Common mistake
With 25% trim waste the factor is not 1.25. If you only add 25%, the extra you bought also loses 25% when trimmed: it is "the waste of the waste", and it never adds up.
Rounding
Both formulas give the same result. Any small difference comes from rounding decimals.
Tip
A factor of 1 means there's no trim: the product is used exactly as purchased.
Calculator
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Result
Fill in the data to see the result and the step-by-step working.