Cow's milk vs Oat milk
Key facts
- Compared
- Cow's milk vs Oat milk
- Unit
- Per per litre
- Metrics
- Greenhouse gases, Land use, Freshwater withdrawal, Calcium (fortified)
- Source
- Poore & Nemecek (2018), Science · Our World in Data · USDA FoodData Central
Per per litre
Source: Poore & Nemecek (2018), Science · Our World in Data · USDA FoodData Central
Verdict
Oat milk uses about a third of the emissions and a tenth of the land.
Questions people ask
Which plant milk is lowest impact overall?
Oat and soy. Soy adds the most protein; oat uses the least water among common options.
Is fortified oat milk nutritionally comparable?
For calcium, B12, D and iodine, fortified versions match or exceed dairy. Protein is lower — soy milk closes that gap.
Related comparisons
Reviewed 2026-09-17 by the Veg.ac editorial team · Data: Poore & Nemecek (2018), Science · Our World in Data · USDA FoodData Central · Free to reuse under CC BY 4.0 with a link back.
How to read this comparison
The figures compare Cow's milk and Oat milk on the same functional unit, so the numbers are directly comparable rather than being two separate claims placed side by side. Life-cycle estimates always carry a range — farming systems, transport distance and processing all shift the result — but the gap between animal and plant options is usually far larger than the uncertainty inside either estimate.
That is the practical point: precision to the last decimal is not what changes anything. The direction and the size of the difference are stable across studies, so a repeated weekly swap between Cow's milk and Oat milk does more than perfect accounting on a single meal ever will.
More questions people ask
Are these numbers accurate for my country?
They are global or regional averages. Local farming intensity, energy grids and transport change the exact figure, but rankings between animal and plant foods hold in nearly every region studied, so the comparison stays useful even when your local number differs.
Does buying local change the answer?
Usually far less than people expect. Transport is a small share of total food emissions for most products, so what you eat generally matters more than how far it travelled. Local buying has other real benefits, but it rarely reverses a comparison like this one.
Is one swap actually worth anything?
One meal is a rounding error; a repeated habit is not. Multiply the difference shown here by fifty to a hundred meals a year and the swap becomes one of the larger changes available to an individual household without changing anything else about how you live.
What about nutrition, not just impact?
The two are separable. A comparison of environmental impact does not tell you whether a meal is balanced. Use the nutrient guides on this site alongside it, and treat protein, iron, B12, calcium and omega-3 as the items worth planning rather than worrying about.