Ecological Footprint Calculator Formula

Understand the math behind the ecological footprint calculator. Each variable explained with a worked example.

Use the Ecological Footprint Calculator

Formulas Used

Total Ecological Footprint

total_gha = carbon_gha + food_gha + housing_gha + goods_gha

Earths Needed

earths_needed = (carbon_gha + food_gha + housing_gha + goods_gha) / 1.6

Carbon Footprint Share

carbon_share = carbon_gha / (carbon_gha + food_gha + housing_gha + goods_gha) * 100

vs World Average (2.7 gha)

vs_world_avg = (carbon_gha + food_gha + housing_gha + goods_gha) / 2.7 * 100

Variables

VariableDescriptionDefault
carbon_tonsAnnual CO2 Emissions(metric tons)12
food_factorFood Footprint Factor(gha multiplier)1.2
housing_sqftHome Size(sq ft)2000
goods_spendingMonthly Goods & Services(USD)1000
carbon_ghaDerived value= carbon_tons * 0.34calculated
food_ghaDerived value= food_factor * 0.9calculated
housing_ghaDerived value= housing_sqft * 0.0003calculated
goods_ghaDerived value= goods_spending * 12 * 0.00005calculated

How It Works

How to Calculate Your Ecological Footprint

The ecological footprint measures how much biologically productive land and sea is needed to support your lifestyle.

Formula

Total gha = Carbon gha + Food gha + Housing gha + Goods gha

Earths Needed = Your Footprint / Earth's Biocapacity per Person

Benchmarks

  • World average: 2.7 gha
  • US average: 8.1 gha
  • Earth's biocapacity: ~1.6 gha per person
  • If everyone lived like Americans, we would need 5 Earths

    • Worked Example

    An American with 12 tons CO2, moderate food, 2,000 sq ft home, $1,000/month spending.

    carbon_tons = 12food_factor = 1.2housing_sqft = 2000goods_spending = 1000
    1. 01Carbon: 12 * 0.34 = 4.08 gha
    2. 02Food: 1.2 * 0.9 = 1.08 gha
    3. 03Housing: 2,000 * 0.0003 = 0.60 gha
    4. 04Goods: 1,000 * 12 * 0.00005 = 0.60 gha
    5. 05Total: 4.08 + 1.08 + 0.60 + 0.60 = 6.36 gha
    6. 06Earths needed: 6.36 / 1.6 = 4.0 planets

    Ready to run the numbers?

    Open Ecological Footprint Calculator