Cow’s milk delivers about 8 grams of protein per cup regardless of whether you choose whole, 2%, or skim. That makes it one of the highest-protein options on the shelf. But if you want even more, ultra-filtered dairy milk and certain plant-based alternatives can match or exceed that number.
Cow’s Milk: Consistent Across Fat Levels
A common misconception is that skim milk has more protein than whole milk, or vice versa. In reality, whole milk, 2% (reduced-fat), and skim milk all contain roughly 8 grams of protein per cup. The only meaningful difference between them is fat and calorie content. Whole milk runs about 150 calories per cup, while skim comes in around 80 calories with virtually no fat.
If you’re trying to get the most protein per calorie, skim milk is the clear winner. You get those same 8 grams of protein for about half the calories of whole milk, which translates to 10 grams of protein for every 100 calories. That ratio is hard to beat among common beverages.
Ultra-Filtered Milk Leads the Pack
Ultra-filtered milk goes through a fine membrane that removes water and lactose while concentrating the protein and calcium left behind. The result is milk with up to 50% more protein than regular milk, putting it in the range of 12 to 13 grams per cup. Brands like Fairlife are the most widely available option in this category. Because the filtration process also breaks down lactose, ultra-filtered milk is typically tolerable for people with lactose sensitivity.
The taste and texture are close to regular milk, just slightly thicker. If your primary goal is maximizing protein from milk, this is the simplest upgrade.
How Plant-Based Milks Compare
Plant milks vary wildly in protein content, and most fall well short of dairy. Here’s how the major options stack up per cup (estimated from per-100g values):
- Soy milk: About 7 to 8 grams of protein, making it the only mainstream plant milk that rivals cow’s milk. A cup of original soy milk has around 110 calories and 8 grams of protein.
- Oat milk: Roughly 2 to 4 grams per cup. Popular for its creamy texture, but not a strong protein source.
- Almond milk: About 1 to 2 grams per cup. It’s low in calories but also low in protein.
- Coconut milk (beverage): Less than 1 gram per cup. Essentially no meaningful protein.
Pea protein milk is a newer category worth noting. Several brands use pea protein isolate to boost their numbers into the 8 to 10 gram range per cup, putting them on par with dairy. Ripple is the most recognized brand in this space. If you avoid both dairy and soy, pea milk is your best bet for protein.
Sheep and Goat Milk
If you have access to milk from other animals, sheep’s milk contains significantly more protein than both cow’s and goat’s milk. It also has more fat, calcium, and total solids, which gives it a richer, thicker consistency. Sheep’s milk is less common in grocery stores but shows up in specialty shops and Mediterranean markets. Goat’s milk is closer to cow’s milk in protein content, typically offering around 8 to 9 grams per cup, with a slightly different flavor profile that some people find easier to digest.
Quick Ranking by Protein Per Cup
- Ultra-filtered cow’s milk: 12 to 13 grams
- Sheep’s milk: 10 to 15 grams (varies by source)
- Cow’s milk (any fat level): 8 grams
- Goat’s milk: 8 to 9 grams
- Soy milk: 7 to 8 grams
- Pea protein milk: 8 to 10 grams
- Oat milk: 2 to 4 grams
- Almond milk: 1 to 2 grams
- Coconut milk: less than 1 gram
Protein Quality Matters Too
Grams per cup only tells part of the story. Dairy milk contains all nine essential amino acids in proportions your body uses efficiently, making it a complete protein. Soy milk is also a complete protein, which is one reason it performs so well as a dairy substitute. Most other plant milks are either incomplete proteins or contain so little protein that the amino acid profile becomes irrelevant.
Dairy protein is split between two types: casein, which digests slowly, and whey, which digests quickly. This combination means dairy milk provides a more sustained release of amino acids compared to a fast-digesting source. For muscle recovery or keeping you full between meals, that slow-and-fast blend is an advantage.
If you’re choosing milk primarily for protein, your top options are ultra-filtered cow’s milk, regular cow’s milk (especially skim for the best protein-to-calorie ratio), soy milk, or pea protein milk. Almond, oat, and coconut milks taste great but contribute almost no protein to your diet.