Wastage Percentage Calculator

Work out wastage percentage instantly with clear inputs, formula shown and shareable results.

About Wastage Percentage Calculator

Wastage as a percentage of purchases is the headline figure, but the split matters more. Spoilage points to over-ordering or poor rotation, preparation waste to portioning and butchery skill, and unexplained waste to recording gaps or losses.

Formulas

Wastage percentage

Wastage % = Wasted value / Total food purchases x 100

Unexplained waste

Unexplained = Total waste - Spoilage - Preparation waste

Worked example

With the default values below, Wastage Percentage Calculator returns Wastage as % of purchases of 6.774%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Value of food wasted: 42,000
Total food purchases: 620,000
Of which spoilage and expiry: 18,000
Of which preparation waste: 14,000

Results

Wastage as % of purchases: 6.774%
Spoilage share of waste: 42.86%
Preparation waste share: 33.33%
Unexplained waste value: $10,000.00

Step by step

1Values used
2Wastage percentage
3Unexplained waste
4Wastage as % of purchases= 6.774
5Spoilage share of waste= 42.86
6Preparation waste share= 33.33
7Unexplained waste value= 10,000.00

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What wastage level is acceptable?

Under 4% of purchases for a well-run kitchen, though fresh-heavy and high-volume prep menus run higher by nature.

What reduces spoilage fastest?

Smaller, more frequent deliveries, strict stock rotation, and cross-utilising ingredients across several dishes so slow lines still move.