Start with the purchase record
Record the package price, package quantity, currency, and purchase unit. Use the amount you actually pay, not a remembered shelf price.
Account for usable yield
Trimming, cooking, peeling, and spoilage reduce usable quantity. Divide purchase cost by usable quantity so the lost product remains in the cost.
Build the batch
Multiply each usable unit cost by the amount used, then add subrecipes. Keep full precision until the final display.
Choose an honest output
Divide by saleable portions, not the theoretical maximum. If a batch produces 23 good portions, do not divide it by 24.
Use your own operating data
Supplier prices, yields, labor rates, and channel fees change. KitchenMargin treats them as editable inputs rather than universal facts.