Food Waste Calculator Formula

Understand the math behind the food waste calculator. Each variable explained with a worked example.

Use the Food Waste Calculator

Formulas Used

Annual Cost of Food Waste

annual_waste_cost = annual_cost

Annual Food Wasted

annual_weight = annual_lbs

CO2 from Wasted Food

co2_from_waste = annual_lbs * 3.8 / 2204.6

Virtual Water Wasted

water_wasted = annual_lbs * 108

Variables

VariableDescriptionDefault
weekly_food_waste_lbsWeekly Food Waste(lbs)5
avg_food_cost_per_lbAverage Food Cost per lb(USD)2.5
household_sizeHousehold Size(people)3
annual_lbsDerived value= weekly_food_waste_lbs * 52calculated
annual_costDerived value= annual_lbs * avg_food_cost_per_lbcalculated

How It Works

How to Calculate Food Waste Impact

About 30-40% of food in the US is wasted, with enormous environmental and financial costs.

Formula

Annual Cost = Weekly Waste * 52 * Cost per lb

Environmental Impact per Pound of Wasted Food

  • CO2: ~3.8 lbs CO2e (includes production, transport, and landfill methane)
  • Water: ~108 gallons (virtual water used in production)
  • Land: ~2.5 sq ft of farmland

    • The average American wastes about 219 lbs of food per year.

    Worked Example

    A 3-person household wasting 5 lbs of food per week at $2.50/lb average.

    weekly_food_waste_lbs = 5avg_food_cost_per_lb = 2.5household_size = 3
    1. 01Annual waste: 5 * 52 = 260 lbs
    2. 02Annual cost: 260 * $2.50 = $650
    3. 03CO2: 260 * 3.8 / 2,204.6 = 0.45 metric tons
    4. 04Water wasted: 260 * 108 = 28,080 gallons

    Ready to run the numbers?

    Open Food Waste Calculator