Compost Volume Calculator Formula

Understand the math behind the compost volume calculator. Each variable explained with a worked example.

Use the Compost Volume Calculator

Formulas Used

Finished Compost

finished_compost = compost_output

Finished Compost

cubic_ft = compost_output / 7.48

Waste Diverted from Landfill

waste_diverted = total_input

CO2 Avoided

co2_saved = total_input * 0.005

Variables

VariableDescriptionDefault
weekly_kitchen_galWeekly Kitchen Scraps(gallons)5
weekly_yard_galWeekly Yard Waste(gallons)10
composting_weeksComposting Period(weeks)52
reduction_pctVolume Reduction(%)65
total_inputDerived value= (weekly_kitchen_gal + weekly_yard_gal) * composting_weekscalculated
compost_outputDerived value= total_input * (1 - reduction_pct / 100)calculated

How It Works

How to Calculate Compost Volume

Composting reduces organic waste volume by 50-75% while producing nutrient-rich soil amendment.

Formula

Finished Compost = Input Volume * (1 - Reduction %)

Volume Reduction

  • Hot composting: 60-75% reduction
  • Cold composting: 50-65% reduction
  • Vermicomposting: 70-80% reduction

    • Composting diverts 30-40% of household waste from landfills.

    Worked Example

    5 gal kitchen scraps and 10 gal yard waste weekly for 52 weeks with 65% volume reduction.

    weekly_kitchen_gal = 5weekly_yard_gal = 10composting_weeks = 52reduction_pct = 65
    1. 01Total input: (5 + 10) * 52 = 780 gallons
    2. 02Finished compost: 780 * (1 - 0.65) = 273 gallons
    3. 03In cubic feet: 273 / 7.48 = 36.5 cu ft
    4. 04CO2 avoided: 780 * 0.005 = 3.9 metric tons

    Ready to run the numbers?

    Open Compost Volume Calculator