Environmental Impact Calculator Formula

Understand the math behind the environmental impact calculator. Each variable explained with a worked example.

Use the Environmental Impact Calculator

Formulas Used

Environmental Impact Score

overall_score = (carbon_score * 0.4 + water_score * 0.2 + waste_score * 0.2 + land_score * 0.2)

Carbon Score

carbon_out = carbon_score

Water Score

water_out = water_score

Waste Score

waste_out = waste_score

Variables

VariableDescriptionDefault
co2_tonsAnnual CO2 Emissions(metric tons)12
water_gal_dayDaily Water Usage(gallons)100
waste_lbs_weekWeekly Waste to Landfill(lbs)25
land_sqftLand Footprint(sq ft)5000
carbon_scoreDerived value= 100 - co2_tons / 16 * 50calculated
water_scoreDerived value= 100 - water_gal_day / 100 * 30calculated
waste_scoreDerived value= 100 - waste_lbs_week / 30 * 30calculated
land_scoreDerived value= 100 - land_sqft / 10000 * 20calculated

How It Works

How to Calculate Environmental Impact Score

An environmental impact score combines multiple factors into a single metric.

Formula

Score = Carbon(40%) + Water(20%) + Waste(20%) + Land(20%)

Each component is scored 0-100 based on comparison to benchmarks:

  • Carbon: US average 16 tons/year
  • Water: 100 gal/day average
  • Waste: 30 lbs/week to landfill
  • Land: normalized to 10,000 sq ft

    • Higher scores indicate lower environmental impact.

    Worked Example

    A person with 12 tons CO2, 100 gal/day water, 25 lbs/week waste, 5,000 sq ft.

    co2_tons = 12water_gal_day = 100waste_lbs_week = 25land_sqft = 5000
    1. 01Carbon: 100 - 12/16*50 = 62.5
    2. 02Water: 100 - 100/100*30 = 70
    3. 03Waste: 100 - 25/30*30 = 75
    4. 04Land: 100 - 5000/10000*20 = 90
    5. 05Overall: 62.5*0.4 + 70*0.2 + 75*0.2 + 90*0.2 = 72.0

    Ready to run the numbers?

    Open Environmental Impact Calculator