Almond milk and oat milk may look interchangeable in coffee, but the ingredient named on the carton tells only part of the nutrition story. In current U.S. unsweetened examples, Silk Unsweet Almondmilk has 30 calories and 1 g protein per cup; Oatly Unsweetened has 40 calories and 0 g protein. Both are low-protein beverages, and much of their calcium comes from fortification.
One cup side by side
| Silk Unsweet Almond | Oatly Unsweetened | |
|---|---|---|
| Calories | 30 | 40 |
| Protein | 1 g | 0 g |
| Fat | 3 g | 1.5 g |
| Carbohydrate | 1 g | 6 g |
| Calcium | 470 mg | 320 mg |
| Vitamin D | 4 mcg | 4 mcg |
The calorie gap is only 10 calories per cup. The larger macro difference is carbohydrate: 6 g in the oat drink versus 1 g in almond milk. Protein is negligible in both.
Neither drink reproduces the nutrition of its whole ingredient
A handful of almonds is rich in fat, fiber, and protein, but almond milk is mostly water and is filtered and formulated to behave like a beverage. Likewise, oat milk does not contain the same concentration of fiber and protein as a bowl of oats.
That is why judging these drinks by the reputation of almonds or oats can be misleading. The finished label matters.
Fortification explains much of the calcium
Silk lists 470 mg calcium per cup and Oatly 320 mg. Both provide 4 mcg vitamin D. Those nutrients are added during manufacturing rather than reflecting a direct transfer from a handful of almonds or a serving of oats.
Fortification varies between brands and product lines, so another almond or oat milk may be much lower. Shake fortified beverages as directed because minerals can settle.
Oat milk has more carbohydrate in this example
Oatly Unsweetened provides 6 g carbohydrate per cup compared with 1 g in the Silk almond drink. Both products are unsweetened, which shows why “unsweetened” and “carbohydrate-free” are not the same thing.
Protein is the weak point for both
One cup provides 1 g protein in almond milk and 0 g in this oat milk. If the beverage is replacing dairy milk as a regular protein source, a higher-protein product—often soy milk—may be a closer nutritional substitute.
Unsweetened and sweetened versions can differ more than almond and oat categories do. Added sugar raises carbohydrate and calories quickly, especially in flavored products. Checking the “added sugars” line is therefore useful when the drink is consumed several times a day rather than only as a splash in coffee.
Fortification needs to be read brand by brand. Calcium and vitamin D are often added, but vitamin B12 and iodine are less consistent. Because calcium salts can settle, shaking the carton before pouring helps the serving match the value printed on the label.
Culinary use may influence the choice. Oat milk’s carbohydrate and starch can give coffee and sauces a fuller texture, while almond milk is often lighter. Barista versions may add oils or stabilizers, improving foam but also changing calories and fat. The best cooking choice is not always the best nutritional match.
If the drink is replacing dairy as a major daily food, protein deserves more weight. Both almond and oat drinks are usually low in protein compared with milk or soy beverages. People relying on them heavily can compensate elsewhere with legumes, tofu, yogurt alternatives, eggs, fish, or other protein foods depending on their diet.
Allergy risk differs between the two. Almond drink is unsuitable for people with tree-nut allergy, while oat drink may require attention to gluten labeling for people with celiac disease because oats can be contaminated with wheat, barley, or rye unless specifically controlled.
Homemade versions are another category entirely. Straining blended oats or almonds with water produces a beverage with variable nutrient content and little or no fortification. If it replaces a fortified commercial product, calcium and vitamin intake can fall unless those nutrients are supplied elsewhere.
Which should you choose?
Choose unsweetened almond milk for a very low-calorie, low-carbohydrate option and oat milk for a different body and flavor profile. Neither product is a meaningful protein source. For calcium, vitamin D, or B12, compare the exact fortified label rather than assuming one plant base always provides more.
Sources
- Silk — Unsweet Almondmilk — Current per-cup label.
- Oatly — Unsweetened Oatmilk — Current per-cup label.
- FDA — Milk and Plant-Based Beverages — Comparison guidance.