Oat vs. Almond vs. Soy vs. Dairy Milk: Protein, Calcium and Price Per Glass

Here is what one glass of each milk delivers, and what it costs. A "glass" is 8 fluid ounces, which USDA weighs at 244 grams for every milk on this list. Prices are our estimates in August 2026 dollars.

*Plant-milk calcium is an average across fortified and unfortified cartons, so no single carton matches it. The section on calcium below splits the two groups.

The winner on protein per dollar is 2% dairy milk. A dollar buys about 26.6 grams of protein, or put the other way, each gram of protein costs about 3.8 cents. Whole milk is a close second at 4.1 cents a gram. Soy comes in at 6.5 cents, and unsweetened almond milk at 32.3 cents.

That almond figure isn't a knock on almond milk. It simply reflects what the carton is: mostly water, with a small amount of almond. If protein is not the reason you're pouring it, the number may not matter to you at all.

The worksheet

Every price in the table comes from the same three steps. We started with the average price per 100 grams from the USDA Economic Research Service's Purchase to Plate price file, which is built from grocery scanner data. We used only rows the agency priced directly from sales, never the ones it filled in by borrowing a price from a similar food.

Those prices are from 2017 and 2018, so step two brings them forward. We multiplied each one by the change in the matching Consumer Price Index series from the Bureau of Labor Statistics, measured from the 2017-18 average to August 2026. Step three multiplies by 2.44 to turn 100 grams into a 244-gram glass.

One nice feature of this setup: protein per dollar is simply protein per 100 grams divided by price per 100 grams. The size of the glass cancels out, so the ranking would be the same whether your glass holds 6 ounces or 12.

If you enjoy this kind of side-by-side, we used a similar approach in our cottage cheese, Greek yogurt and skyr showdown.

The ranking comes down to two numbers moving in opposite directions. On protein, soy and dairy are near twins. On price, they are not.

Start with the protein. USDA's lab-analyzed record for unsweetened soy milk in FoodData Central shows 3.55 grams of protein per 100 grams, which works out to 8.7 grams a glass. Whole dairy milk measures 3.27 grams per 100, or 8.0 grams a glass, and 2% milk sits at 8.2. So on average, a glass of unsweetened soy milk edges out a glass of dairy milk on protein.

It is a small edge, and the samples overlap. USDA's soy cartons ranged from 3.0 to 4.7 grams per 100 grams, while whole milk samples ranged from 2.9 to 3.5. The fair reading is that the two are in the same neighborhood, with soy a touch higher.

Now the price. Our estimate puts a glass of soy milk at about 56 cents and a glass of 2% milk at about 31 cents. That is roughly 1.8 times the cost for about the same protein, which is why 2% milk delivers 1.7 times as much protein per dollar. For soy to tie, its price would need to drop by about 42%.

Almond and oat milk tell a different story. Each carries less than 2 grams of protein a glass on USDA's records, about a fifth of what dairy or soy provides. Even at a lower price than soy, almond milk's protein per dollar is about one-eighth of 2% milk's.

There is a caveat worth naming on the soy number. Our soy protein comes from an unsweetened carton, while the soy price is an average across sweetened and unsweetened ones. If we swap in USDA's record for sweetened soy milk, which is a bit more diluted, soy drops to about 12.1 grams of protein per dollar. The order of the ranking does not change either way.

Curious how milk stacks up against eggs, beans and chicken on the same yardstick? Our ranking of 25 foods by protein per dollar puts them all on one list.

Whenever we estimate a price, we like to hold it up against a second, independent number. For dairy milk there is a good one.

The Bureau of Labor Statistics publishes an average price for a gallon of whole milk every month. For August 2026, the BLS average price for a gallon of fresh whole milk was $4.229. A gallon holds 16 glasses, so that comes to about 26 cents a glass. The matching series for low-fat and reduced-fat milk was $3.715 a gallon, or about 23 cents a glass.

Our estimates were higher: 32 cents for whole and 31 cents for 2%. That puts our whole-milk figure about 23% above the gallon price, and our 2% figure about 33% above.

We looked into why, and the gap turns out to be built in rather than a mistake in the inflation step. Back in 2017 and 2018, the scanner-based price was already about 25% higher than the gallon price. The reason is what each one measures. The gallon series tracks gallon jugs only. The scanner file averages every container of milk sold, including quarts, half gallons and organic milk, which all cost more per ounce.

That difference is useful in its own right. It suggests the gallon jug is the least expensive way dairy milk is sold, by a comfortable margin. On gallon prices, whole milk reaches about 30 grams of protein per dollar and low-fat milk about 35. So if anything, our table understates dairy's lead for households that buy by the gallon.

We ran a related comparison on drinks marketed for after exercise in our chocolate milk, sports drink and protein shake showdown.

Protein in these milks comes from the soybean, the almond, the oat or the cow. Calcium is a different matter. In dairy milk it is there naturally and it barely varies: USDA's whole milk samples ranged only from 116 to 130 mg per 100 grams. In plant milks, nearly all of it is added at the factory, and some cartons skip that step entirely.

You can see this in USDA's own data. Its unsweetened almond milk samples ranged from about 9 mg to 225 mg of calcium per 100 grams. Soy ranged from 11 to 160, and oat from 48 to 300. Those are not small wobbles. They are two different kinds of product averaged into one line.

So we pulled them apart. The table below covers 16 widely sold plain cartons, unsweetened wherever the brand offers one, grouped by whether the ingredient list includes an added calcium salt. Values are per 240 mL serving, as the label states them.

A few patterns jump out. Fortified almond milk carries the most calcium on the label, at 440 to 470 mg a glass, roughly half again as much as dairy milk's 300. Fortified soy and oat cartons land between 260 and 350. The unfortified cartons, the ones with two or three ingredients, carry between 7 and 40 mg.

There is a trade-off hiding in that table, too. The short-ingredient cartons tend to have more of the actual plant in them, so they carry more protein: 4 to 5 grams for the almond milks instead of 1, and 9 to 12 grams for the soy milks instead of 7 or 8. More protein, almost no calcium. Neither choice is wrong. They are simply different products sharing a shelf.

For context on what those milligrams mean, the Daily Value for calcium on U.S. labels is 1,300 mg, according to the National Institutes of Health Office of Dietary Supplements. The same fact sheet notes that calcium absorption from dairy products and fortified foods is about 30%. It does not rank one added form of calcium against another, and neither will we.

One practical wrinkle is worth knowing. Added calcium is a mineral powder suspended in the liquid, and it can drift toward the bottom of the carton as it sits. Researchers have written about this, including a 2006 paper titled The Settling Problem in Calcium-Fortified Soybean Drinks in the Journal of the American Dietetic Association. We could not access the full paper, so we are not quoting figures from it. The takeaway we are comfortable with is modest: the label describes the carton as a whole, which is not necessarily what lands in each pour.

On calcium per dollar, dairy still leads at 926 to 998 mg, but fortified almond milk comes close. A fortified almond carton at 450 mg a glass works out to roughly 870 mg per dollar at our estimated price. Unfortified cartons drop to about 60 to 70 mg per dollar.

If calcium is the nutrient you are shopping for, our ranking of 15 non-dairy calcium sources looks at foods beyond the milk case.

Sugar is not part of our ranking, but it is the label line that surprises people most, so it deserves a short stop.

Dairy milk shows 11.7 to 11.9 grams of total sugars a glass on USDA's records. That is lactose, the sugar that occurs naturally in milk, and the added-sugars line on a plain dairy carton reads zero. Unsweetened soy shows about 1.4 grams, and unsweetened almond rounds to zero.

Oat milk is the odd one out. USDA's lab record for unsweetened oat milk measured 2.3 grams of sugars per 100 grams, or 5.7 grams a glass, with no sweetener involved. The explanation is in how oat milk is made. Enzymes are used to break down oat starch so the drink turns smooth and pourable, and that process creates sugars such as maltose along the way.

Here is where the label gets interesting. The Food and Drug Administration's guidance on added sugars says sugars created this way in plant-based beverages, and it names oat and rice drinks specifically, need to be declared as added sugars on the Nutrition Facts panel. That is true even though nothing sweet was poured in.

You can see the rule at work on a real carton. The label for Oatly's Original oat milk lists 7 grams of added sugars per cup, with no sugar or syrup anywhere in the ingredients, and a footnote explaining that the added sugars are created when the oats are liquefied.

Not every oat milk lands in the same place. Planet Oat's Unsweetened Original declares 0 grams of total and added sugars. The difference comes down to how each maker processes the oats, which is another reason the panel on the specific carton tells you more than the word "oat" on the front.

We took a similar per-glass look at fruit drinks in our cider, juice and whole apple comparison.

You may have wondered whether a carton made from almonds is even allowed to say "milk." For now, the answer is yes.

In February 2023, the Food and Drug Administration released a draft guidance on labeling plant-based milk alternatives. It says names like "soy milk" and "almond milk" have become established through common use, and that these products may be labeled as a beverage, a drink or a milk.

The draft also suggests something voluntary. When a plant milk uses the word "milk" and has a different nutrient makeup from dairy, the agency recommends a short statement on the package, along the lines of "Contains lower amounts of" a named nutrient "than milk." The comparison point it uses is the USDA Food and Nutrition Service's nutrient criteria for fluid milk substitutes, which include 8 grams of protein and 276 mg of calcium per cup.

Two things are worth holding onto here. First, this is still a draft. As of our check in October 2026, the agency had not issued a final version, and the document itself is marked as not for implementation. Second, those two benchmark numbers make a handy yardstick. On USDA's records, soy is the only plant milk in our comparison that reaches 8 grams of protein, and unfortified cartons of any kind fall far short of 276 mg of calcium.

Federal dietary guidance draws a similar line. The agency notes that fortified soy beverages are the only plant-based milk alternative the Dietary Guidelines for Americans count in the dairy group. That lines up with what the per-glass numbers show: soy behaves like dairy on protein, and almond and oat do not.

All of this boils down to a few things you can check in about ten seconds, right there at the shelf.

The first is the protein line. A glass of dairy or soy milk will typically show 7 to 9 grams. Most almond and oat milks show 1 to 3. If protein is part of why you're buying, that single line does most of the sorting for you.

The second is the ingredient list, scanned for the word "calcium." Calcium carbonate and tricalcium phosphate are the two you'll see most often. If neither appears, the carton is unfortified, and the calcium line on the panel will usually be in the low double digits.

The third is the added-sugars line, especially on oat milk. As we saw, it can show several grams even when no sweetener is listed. In the USDA label records we reviewed, "original" soy and almond milks from the largest brands declared about 5 to 7 grams of added sugars a cup, which the unsweetened versions do not carry.

And if you are weighing a wider set of options, from pea to coconut to rice, our guide comparing popular milk alternatives covers more of the shelf.

No single milk wins every column. Dairy takes protein per dollar and calcium per dollar. Soy takes protein per glass among the plant milks and comes closest to dairy overall. Fortified almond milk takes label calcium. Oat milk's strengths are not ones this table measures. Knowing which column matters most to you is what turns a wall of cartons back into a simple choice.