Soy milk has the most protein of any standard non-dairy milk, delivering about 8 to 11 grams per cup depending on the brand. That matches regular cow’s milk almost exactly. If you want even more, a newer product called Silk Protein pushes to 13 grams per cup by blending multiple plant proteins together.
Soy Milk Leads the Pack
Plain soy milk consistently lands between 8 and 11 grams of protein per cup. That range depends on how concentrated the soy base is and whether the product is sweetened or unsweetened (unsweetened versions tend to have slightly more protein per calorie). Soy is the only plant milk where the protein comes entirely from the base ingredient itself, not from added protein isolates. It also has a complete amino acid profile, meaning it contains all nine essential amino acids your body can’t make on its own.
This matters because protein quality varies between plant sources. Soy protein is absorbed and used by the body more efficiently than most other plant proteins. Your body treats it similarly to dairy protein, which is why soy milk has long been the go-to recommendation for people replacing cow’s milk and wanting comparable nutrition.
Pea Milk Is a Close Second
Pea milk, made from yellow split peas, typically delivers 8 grams of protein per cup. Ripple, the most widely available brand, hits that mark while also providing 50% more calcium than 2% dairy milk. At 90 calories per cup for the original version, it’s a solid option if you need to avoid soy due to allergies or personal preference.
Pea protein is slightly lower in one amino acid (methionine) compared to soy, but for most people eating a varied diet, that gap is meaningless. You’ll get enough methionine from grains, nuts, and other foods throughout the day. Where pea milk stands out is taste and texture. Many people find it creamier and more neutral than soy milk, which can have a slight beany flavor.
High-Protein Blends Push Past Dairy
If maximizing protein is your priority, blended plant milks now outperform even cow’s milk. Silk Protein Original packs 13 grams of protein per cup, which ties with ultra-filtered dairy milk and surpasses regular milk’s 8 grams. It achieves this by combining multiple plant protein sources, which also helps balance out the amino acids that any single plant protein might lack.
The Center for Science in the Public Interest found that no other major brand currently tops Silk Protein’s 13 grams. This category is growing quickly, though, so other options at the 10 to 13 gram range may appear on shelves. When evaluating these products, check the sugar content. Some high-protein plant milks add sugar to improve flavor. Silk Protein Original keeps added sugar moderate, but flavored versions of any brand can spike significantly.
Most Plant Milks Are Protein-Poor
Here’s the reality that surprises many people: outside of soy and pea milk, most plant milks contain almost no protein. A large review published in Frontiers in Nutrition found that the majority of non-dairy milks have 1% protein or less, making them poor substitutes if you’re counting on that glass of milk for meaningful nutrition.
The numbers tell the story clearly:
- Almond milk: about 1 gram of protein per cup
- Oat milk: about 1 to 2 grams per cup
- Coconut milk: under 1 gram per cup
- Rice milk: the lowest of all, often under 1 gram per cup
These milks are fine for cooking, coffee, or cereal if protein isn’t your concern. But if you’re swapping out dairy milk and relying on that cup as part of your daily protein intake, almond or oat milk won’t come close to filling the gap. You’d need roughly 8 cups of almond milk to match the protein in a single cup of soy milk.
How to Choose the Right One
Your best pick depends on what you’re optimizing for. If you want the simplest, most widely available high-protein option with minimal ingredients, unsweetened soy milk is hard to beat. It’s been on shelves for decades, it’s inexpensive, and it delivers 8 to 11 grams of complete protein with no added protein powders.
If you dislike soy or have an allergy, pea milk gives you 8 grams with a milder flavor. For people tracking macros or trying to hit higher protein targets, one of the blended options like Silk Protein gets you to 13 grams, which is genuinely useful if you’re adding it to smoothies or drinking a couple of glasses a day.
Whatever you choose, flip the carton and look at three things: protein grams, added sugar, and calcium. Many plant milks are fortified with calcium and vitamin D to match dairy, but not all brands do this equally. A plant milk with 8 grams of protein, low added sugar, and at least 20% of your daily calcium value per cup is nutritionally comparable to cow’s milk for most purposes.