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Vegan impact calculator
Animals not slaughtered, CO2 not emitted, water not used. Based on peer-reviewed research, not the figures most vegan calculators recycle.
year
Decimals work too (0.5 = 6 months). Estimates compare a vegan diet to the average omnivorous diet.
Land animals
30
cows, pigs, chickens, etc.
Sea animals
200
fish, shellfish, bycatch
CO2e avoided
750 kg
vs average diet
Water saved
1.1M L
green + blue water footprint
Land spared
2.5k m²
cropland + pasture
Total animals
230
land + sea, lifetime
That CO2 saved is equivalent to
0.2
fraction of a car off the road for a year
0.4
fraction of a transatlantic flight
030 yrs60 yrs
Future animals
4.6k
Future CO2
15k kg
How we calculated this
These are estimates with real variance - food systems differ by country, farming practice, and study methodology. We use peer-reviewed sources and pick conservative midpoints rather than the highest-impact numbers other vegan calculators sometimes cite.
- Animals (~230/year) - Harish Sethu's analysis at Counting Animals, derived from USDA and NOAA slaughter data. Updated figures in line with Faunalytics reports.
- CO2e (~750 kg/year) - Midpoint of Scarborough et al. 2023 (Nature Food) [link] and Poore & Nemecek 2018 (Science) [link]. Vegans emit ~75% less from food than high-meat eaters; vs the average diet the saving is smaller.
- Water (~1.1M L/year) - Differential between vegan and omnivorous diet water footprints in Mekonnen & Hoekstra 2012 [PDF]. Includes green (rainfall) and blue (irrigation) water; the figure shrinks if you only count blue water.
- Land (~2,500 m²/year)- Poore & Nemecek 2018. A vegan diet uses ~76% less agricultural land than the global average diet. We use a conservative average.
Why we don't cite Cowspiracy's figures: several of them (1,100 gallons water per almond, 660 gallons per burger) don't hold up under peer review. The numbers here are smaller but defensible.