A standard eight-ounce glass of whole cow’s milk delivers roughly 320 to 350 milligrams of potassium, making it one of the more potassium-dense beverages most people drink regularly. Plant-based alternatives, however, spread across an enormous range: some match or even beat cow’s milk, while others contain almost none. The gap between the best and worst options is wide enough to matter if you’re tracking your potassium intake for health reasons.
How Much Potassium Is in a Glass of Cow’s Milk
Whole cow’s milk contains an average of about 134 milligrams of potassium per 100 grams, which works out to roughly 322 to 350 milligrams in a typical eight-ounce (240 ml) serving.1PubMed Central. Mineral content of market samples of fluid whole milk That single glass covers about 10 percent of the adequate daily intake for an adult man (3,400 mg) or about 13 percent for an adult woman (2,600 mg). Among common beverages, that makes milk a strong potassium source, roughly on par with a medium banana.
The fat content of the milk changes this only modestly. Skim and low-fat milks tend to have slightly more potassium per serving than whole milk, because removing fat concentrates the water-soluble minerals. The difference is small enough that switching between whole and skim won’t meaningfully change your potassium intake.
One thing that varies more than you’d expect is the mineral profile from one carton to the next. In a study analyzing market samples of fluid whole milk, the coefficient of variation for potassium was around 18 to 26 percent, meaning there’s a noticeable spread even among cartons on the same shelf.1PubMed Central. Mineral content of market samples of fluid whole milk That variation comes from differences in breed, season, geography, and what the cows are eating, though for most people the practical effect is minor.
Plant-Based Alternatives Span a Huge Range
If you’ve swapped cow’s milk for a plant-based alternative, the potassium you’re getting depends entirely on which one you chose. A study that measured the nutrient content of commercially available plant milks found potassium values ranging from essentially zero to nearly 400 milligrams per cup.2PubMed Central. Plant-Based Milk Alternatives and Risk Factors for Kidney Stones and Chronic Kidney Disease That’s not a gentle gradient; it’s a cliff between the top and the bottom of the category.
Here’s how the main plant milks stacked up per eight-ounce serving in that analysis:
- Oat milk: about 390 mg, slightly more than cow’s milk
- Soy milk: about 380 mg, very close to cow’s milk
- Hemp milk: about 145 mg, roughly half of cow’s milk
- Cashew milk: about 94 mg
- Macadamia milk: about 10 mg
- Almond milk: 0 mg measured in the tested brand
The zero reading for almond milk is striking, and it’s the single most important thing for anyone switching from dairy to know. Almonds themselves are a good source of potassium, but almond milk is mostly water with a small amount of almond content, and the potassium either doesn’t survive processing in meaningful amounts or simply isn’t present in the quantities used. Soy milk and oat milk, on the other hand, deliver potassium in the same ballpark as cow’s milk, making them the best plant-based options if potassium matters to you.2PubMed Central. Plant-Based Milk Alternatives and Risk Factors for Kidney Stones and Chronic Kidney Disease
Why the Numbers Differ So Much Between Plant Milks
The variation comes down to what the plant milk is actually made of and how much of it ends up in the final product. Soy milk uses whole soybeans, which are rich in potassium, and the beans are blended in a high enough concentration to carry their minerals into the drink. Oat milk is similarly dense in its base ingredient. Almond milk and macadamia milk, by contrast, often contain only 2 to 3 percent actual nuts by weight. The rest is water, stabilizers, and added vitamins. At those concentrations, whatever potassium the nuts contain gets diluted into near-irrelevance.
This also explains why two brands of the same type of plant milk can differ quite a bit. A brand that uses more of the base ingredient, or processes it differently, may retain more minerals. A study examining plant-based milks on the Italian market found that mineral content varied widely even within the same category. The researchers concluded that nutritional standards cannot be set uniformly for a given type of plant-based milk, and that mineral content was actually the biggest factor differentiating one product from another.3MDPI Foods / PubMed Central. Assessment of the Accuracy of Nutrition Label and Chemical Composition of Plant-Based Milks Available on the Italian Market
The practical takeaway is that you can’t just pick “almond milk” or “oat milk” as a category and assume you know the potassium content. Brands matter, formulations change, and the label is your best starting point, though as we’ll see, even labels aren’t always reliable.
When the Label Doesn’t Match What’s Inside
Potassium labeling on plant-based milks has a credibility problem. Unlike calcium and vitamin D, which manufacturers actively fortify and prominently advertise, potassium is rarely added during production. Many plant milks simply don’t list potassium on the nutrition facts panel, or list it as zero because it falls below the threshold the manufacturer chose to report. That doesn’t necessarily mean the drink contains no potassium, but it does mean the consumer is often flying blind.
The Italian market study referenced above found that the chemical composition of plant-based milks frequently diverged from what the labels claimed. The mineral profiles in particular showed enough variation that the researchers flagged it as a quality-control issue.3MDPI Foods / PubMed Central. Assessment of the Accuracy of Nutrition Label and Chemical Composition of Plant-Based Milks Available on the Italian Market This is not unique to Italian products. Plant-based milks are a relatively young commercial category, and the regulatory infrastructure for verifying mineral content on labels has not caught up to the pace of new products hitting shelves. If you’re relying on a specific potassium number for medical reasons, treating any plant milk label as an approximation rather than a guarantee is the safer approach.
Why Potassium in Your Daily Milk Matters
Potassium is one of those nutrients most people don’t think about until a doctor mentions it. But chronic low potassium intake is common, and it has a direct relationship with blood pressure. A meta-analysis of randomized controlled trials found that increasing potassium intake reduced systolic blood pressure by about 4.7 mmHg and diastolic blood pressure by about 3.5 mmHg across all participants. In people who already had high blood pressure, the effect was even larger: systolic dropped by roughly 6.8 mmHg and diastolic by about 4.6 mmHg.4PubMed Central. Daily potassium intake and sodium-to-potassium ratio in the reduction of blood pressure: a meta-analysis of randomized controlled trials
That’s a meaningful effect, comparable to what some people achieve with a low-dose blood pressure medication. Potassium helps because it counteracts sodium: the ratio between the two in your diet matters at least as much as the absolute amount of either one alone. The same meta-analysis showed that decreasing the sodium-to-potassium ratio was associated with blood pressure reduction independently of just increasing potassium.4PubMed Central. Daily potassium intake and sodium-to-potassium ratio in the reduction of blood pressure: a meta-analysis of randomized controlled trials
This is where milk choice becomes a low-effort lever. If you drink two glasses of milk a day, switching from a brand of almond milk with near-zero potassium to soy or oat milk adds roughly 700 to 780 milligrams of potassium to your daily intake without changing anything else about your diet. For someone eating a typical Western diet that’s already low in potassium, that kind of swing is a real shift toward the recommended range.
Potassium and Kidney Disease: When More Is Not Better
There’s an important flip side. For people with impaired kidney function, extra potassium is not a benefit; it’s a risk. Healthy kidneys are efficient at excreting excess potassium, but when kidney filtration declines, potassium builds up in the blood. Elevated blood potassium, known as hyperkalemia, can cause dangerous heart rhythm disturbances. This is why people with chronic kidney disease are often counseled to limit high-potassium foods, including dairy milk.
In this context, the low-potassium plant milks that seem nutritionally inferior for the general population become the better choice. Almond milk, macadamia milk, and rice milk, with their minimal potassium content, are often specifically recommended for people on potassium-restricted diets. The study that measured potassium across plant milks was actually conducted in the context of kidney stone and chronic kidney disease risk, precisely because choosing the right milk substitute can make a clinically significant difference in daily potassium load for these patients.2PubMed Central. Plant-Based Milk Alternatives and Risk Factors for Kidney Stones and Chronic Kidney Disease
So the “best” milk for potassium depends entirely on your kidneys. If they work normally, higher potassium is generally desirable. If they don’t, the opposite is true. This is one of the few food-choice decisions where the right answer for one group of people is the wrong answer for another, and the stakes aren’t trivial.
Goat Milk, Camel Milk, and Other Animal Milks
If your milk alternatives extend beyond the plant-based aisle and into other animal milks, the potassium picture stays fairly consistent with cow’s milk. Goat milk contains a similar amount of potassium per serving, typically within 10 to 15 percent of cow’s milk values. The mineral profiles of the two are close enough that switching between them won’t change your potassium intake in a meaningful way.
Camel milk is a bit more interesting. A review of the mineral content of camel milk found potassium levels ranging from 124 to 209 milligrams per 100 grams, compared to 130 to 160 milligrams per 100 grams in cow’s milk.5Europe PMC. Mineral status in camel milk: a critical review. The upper end of the camel milk range pushes about 30 percent above the average for cow’s milk, making it potentially one of the highest-potassium animal milks available. That said, camel milk is expensive and hard to find in most markets, so it’s more of a curiosity than a practical recommendation for most people.
Sheep milk tends to be more concentrated overall due to its higher total solids content, and its potassium levels are generally at or slightly above those of cow’s milk. Buffalo milk follows a similar pattern. Across all common dairy animals, potassium hovers in a relatively tight band between about 120 and 210 milligrams per 100 grams. The dramatic variation you see in the plant-based category simply doesn’t exist among animal milks.
How Processing Shifts the Potassium Content
Most people think of milk as a simple, unprocessed product, but commercial milk goes through multiple steps before it reaches your glass, and some of those steps redistribute minerals. Pasteurization, the heat treatment that kills harmful bacteria, has minimal effect on potassium because potassium is a dissolved mineral rather than a heat-sensitive molecule. Your pasteurized milk and raw milk have essentially the same potassium content.
Ultrafiltration is a different story. This process pushes milk through membranes to separate its components, and it’s used to make products like ultrafiltered milk (sometimes marketed as “high-protein” milk), Greek yogurt base, and certain cheese ingredients. Research on whole-milk ultrafiltration has shown that potassium, being a small dissolved ion, passes through the filtration membrane into the permeate, the liquid fraction that gets separated out.6Europe PMC. Ultrafiltration of Whole Milk: Impact of Homogenization and Ultrafiltration Temperature on Processing Efficiency and Component Retention. That means the retained portion, which is the concentrated product you’d buy as ultrafiltered milk, can end up with a different potassium concentration than regular milk. Whether it’s higher or lower depends on how the final product is formulated and diluted.
For products like yogurt and cheese, the story gets more complicated because fermentation and whey removal also pull potassium out. A cup of yogurt typically has less potassium per serving than a cup of milk from the same amount of starting dairy, because some potassium leaves with the whey. Hard cheeses concentrate some minerals but lose others in the whey, so cheese is not a reliable substitute for milk’s potassium content despite being a dairy product.
Flavored Milks, Chocolate Milk, and Fortified Options
Chocolate milk deserves its own mention because it’s popular, especially with kids and athletes, and its potassium content is often higher than plain milk. The added cocoa is a potassium-containing ingredient. A cup of chocolate milk typically delivers about 400 to 420 milligrams of potassium, roughly 20 to 25 percent more than plain milk. This makes chocolate milk one of the highest-potassium single-serving dairy beverages you can easily buy.
On the plant-based side, flavored versions like vanilla or chocolate soy milk don’t follow the same pattern. The added flavoring contributes negligible potassium, and the sugar or sweetener dilutes the base ingredient somewhat. You’ll see similar or slightly lower potassium numbers compared to the unflavored version of the same brand.
Fortification is the wild card. Some manufacturers have begun adding potassium to plant-based milks, though it’s far less common than calcium or vitamin D fortification. When a plant milk is fortified with potassium, its label will say so, and the potassium content can jump considerably. This is a newer trend, and it’s unevenly applied across the market. Checking the nutrition panel for actual milligrams, rather than assuming a given type of plant milk has a fixed potassium level, is still the most reliable approach.
Putting It All Together at the Grocery Store
If you’re standing in the dairy aisle trying to make a practical decision, the landscape simplifies into a few categories. Cow’s milk in any fat percentage gives you roughly 320 to 350 milligrams of potassium per cup. Soy milk and oat milk are the plant-based options that match that range. Hemp milk gets you about halfway there. Everything else on the plant-based shelf, including almond, macadamia, rice, and coconut milks, delivers little to no potassium per serving.
For most adults, who are already falling short of the recommended 2,600 to 3,400 milligrams of potassium per day, the high-potassium options are preferable. For people managing kidney disease or taking medications that raise blood potassium levels, the low-potassium options are the safer bet. And for everyone, the specific brand matters more than the type on the label, because formulations within each plant-milk category vary enough that two oat milks from different companies can tell different nutritional stories. Flip the carton over, read the panel, and let the actual milligrams guide your choice rather than any assumption about what “oat milk” or “almond milk” should contain.