Food Waste Percentage Calculator

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

About Food Waste Percentage Calculator

Waste percentage is discarded weight over purchased weight, and the value discarded is that weight times the purchase price per kilogram. Annualising a weekly figure is what makes waste visible: six kilograms a week at three per kilogram is over nine hundred a year straight into the bin.

Formulas

Waste percentage

waste % = wasted weight / purchased weight x 100

Annual cost

annual = wasted weight x cost per kg x 52

Worked example

With the default values below, Food Waste Percentage Calculator returns Waste percentage of 12.00%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Food purchasedminimum 0.1 kg: 50 kg
Food thrown awayminimum 0 kg: 6 kg
Cost per kgminimum 0.01: 3

Results

Waste percentage: 12.00%
Value thrown away: $18.00
Food actually used: 44.00 kg
Cost if repeated weekly for a year: $936.00

Step by step

1Values used
2Waste percentage
3Annual cost
4Waste percentage= 12.00
5Value thrown away= 18.00
6Food actually used= 44.00 kg
7Cost if repeated weekly for a year= 936.00

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 2 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

How is the Food Waste Percentage figure worked out?

waste % = wasted weight / purchased weight x 100. Waste percentage is discarded weight over purchased weight, and the value discarded is that weight times the purchase price per kilogram.

Why does this matter?

Annualising a weekly figure is what makes waste visible: six kilograms a week at three per kilogram is over nine hundred a year straight into the bin.

What do I need to enter?

Enter food purchased, food thrown away, cost per kg. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.