Establish the measurement and quote basis
State whether loss is a fraction of gross input or an added allowance on net output. These are different mathematical definitions.
Record the SKU, date, source document and unit beside the observation. Mark an estimate as provisional so it cannot be mistaken for supplier-confirmed data.
Worked purchasing example
For 1,000 kg good output and 5% gross-input loss, gross need is 1,000/0.95 = 1,052.632 kg. Adding 5% instead gives 1,050 kg, whose 95% yield is only 997.5 kg.
These figures are illustrative arithmetic, not market prices or a promised saving. Replace them with measurements and offers covering your actual job.
Turn the result into a decision
Use the convention requested by the calculator and retain the source measurement. Do not apply the same reject allowance again when a supplier prices accepted good pieces.
Use the linked calculator to check the same boundary, then include complete known order charges in comparison. Preserve unresolved items in the specification rather than replacing them with zero.
Common questions
Can several loss rates simply be added?
Not generally. Sequential yields multiply when each loss is defined on its own stage input. Avoid mixing startup scrap, running loss and finished rejection without a stage-by-stage boundary.
Are the example prices current supplier quotes?
No. They are illustrative values chosen to demonstrate the calculation. Enter current confirmed offers for the same specification and quantity.