Calories in Walnuts: Nutrition Facts & Serving Sizes
Per 1 cup halves (50g)
Per 100g
Source: Web research, March 2026.
One ounce of walnuts (28g) contains 183 calories with 4.3g of protein, 3.8g of carbs, and 18.3g of fat. Per 100g, walnuts provide 654 calories, 15.2g of protein, 13.7g of carbs, and 65.2g of fat. Walnuts are one of the most calorie-dense foods you can eat, so portion control is critical when tracking macros. The standout nutritional feature is the fat profile: walnuts contain 47.2g of polyunsaturated fat per 100g, the highest of any common nut. This includes a significant amount of ALA (alpha-linolenic acid), a plant-based omega-3 fatty acid. They also provide 441mg of potassium, 158mg of magnesium, and 98mcg of folate per 100g. For those focused on fitness, walnuts are a calorie-dense snack that delivers healthy fats and decent protein in a small package. Measure by the ounce to avoid accidentally eating 400 to 500 calories in one sitting.
Nutrition Highlights
Calories by Serving Size
| Serving | Cal | Protein | Carbs | Fat | Fiber |
|---|---|---|---|---|---|
| 1 oz (28g) | 183.1 | 4.3g | 3.8g | 18.3g | 1.9g |
| 1 cup halves (50g) | 327 | 7.6g | 6.9g | 32.6g | 3.4g |
| 100g | 654 | 15.2g | 13.7g | 65.2g | 6.7g |
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Full Nutrition Facts (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 654 | 33% |
| Protein | 15.2g | 30% |
| Total Fat | 65.2g | 84% |
| Saturated Fat | 6.1g | 31% |
| Total Carbohydrates | 13.7g | 5% |
| Dietary Fiber | 6.7g | 24% |
| Sugars | 2.6g | 5% |
| Sodium | 2mg |
Vitamins & Minerals (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Saturated Fat | 6.1g | 2% |
| Calcium | 98mg | 8% |
| Iron | 2.9mg | 16% |
| Potassium | 441mg | 9% |
| Vitamin A | 1mcg | 0% |
| Vitamin C | 1.3mg | 1% |
| Vitamin B6 | 0.5mg | 29% |
| Magnesium | 158mg | 38% |
| Phosphorus | 346mg | 28% |
| Zinc | 3.1mg | 28% |
| Selenium | 4.9mcg | 9% |
| Folate | 98mcg | 25% |
| Thiamin (B1) | 0.3mg | 25% |
| Riboflavin (B2) | 0.2mg | 15% |
| Niacin (B3) | 1.1mg | 7% |
% Daily Values based on a 2,000 calorie diet (FDA reference).
Health Benefits of Walnuts
Walnuts have one of the strongest research bases of any nut. The 47.2g of polyunsaturated fat per 100g is dominated by ALA, which the body converts to EPA and DHA omega-3 fatty acids. Omega-3s have well-documented anti-inflammatory effects, which matters for anyone doing high-volume training with significant muscle damage and inflammation.
The 158mg of magnesium per 100g is a significant benefit for active people. Magnesium is involved in over 300 enzymatic processes, including muscle contraction, energy production from ATP, and protein synthesis. Many people training intensely are depleted in magnesium through sweat, and walnuts are an easy way to boost intake.
Walnuts also contain 441mg of potassium per 100g, supporting electrolyte balance and preventing muscle cramps. The 98mcg of folate per 100g supports DNA synthesis and cell repair, relevant when training is damaging and rebuilding muscle tissue at a high rate.
The 6.7g of fiber per 100g slows digestion, which blunts the glycemic response and contributes to satiety. Despite being extremely calorie-dense, a measured 1 oz serving of walnuts is genuinely filling due to the combination of fat, protein, and fiber.
For practical use: add walnuts to oatmeal, mix into Greek yogurt, or eat 1 oz as a between-meal snack. Just keep a food scale nearby since visually estimating portions of any nut is unreliable and can lead to significant calorie overages.
Dietary Considerations
Walnuts are naturally gluten-free, vegan, and dairy-free. They are not keto-friendly if eaten in large amounts due to their carb content, but 1 oz (3.8g carbs) fits comfortably within keto macros. For weight loss, walnuts require strict portion control at 654 calories per 100g. A measured 1 oz serving works well as a snack, but free-handing walnuts from a bag is an easy way to eat 400 to 600 calories without realizing it. Despite the calorie density, research suggests nut consumers tend to have better weight management outcomes than non-consumers, likely due to the satiety effects of fat, protein, and fiber combined.
Daily Intake (100g)
100g of walnut provides 33% of a 2,000-calorie diet.
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Frequently Asked Questions
How many calories in walnuts?
One ounce of walnuts (28g, about 14 halves) has 183 calories. Per 100g, walnuts contain 654 calories. A half cup (50g) has 327 calories. Walnuts are extremely calorie-dense, so weigh your portions rather than estimating by volume.
Are walnuts good for weight loss?
Walnuts can support weight loss in controlled portions. The combination of fat (18.3g per oz), protein (4.3g per oz), and fiber (1.9g per oz) makes them very satiating. Research shows walnut consumers often eat fewer total calories despite the high calorie density of the nuts themselves. Stick to 1 oz servings.
How much protein in walnuts?
One ounce of walnuts (28g) has 4.3g of protein. Per 100g, walnuts contain 15.2g of protein. While higher than most fruits and vegetables, walnuts are not a primary protein source. Use them for healthy fats and micronutrients, and get your main protein from meat, eggs, or dairy.
Are walnuts high in omega-3s?
Yes, walnuts are the richest common food source of plant-based omega-3s (ALA). Per 100g, walnuts contain 47.2g of polyunsaturated fat, much of it ALA. While ALA is not as directly usable as the EPA and DHA from fish, walnuts still contribute meaningfully to omega-3 intake for anti-inflammatory support.
How many walnuts should I eat per day?
Most research on walnut health benefits uses 1 to 2 oz per day (28 to 56g). At 183 to 327 calories, this is a reasonable daily range that provides meaningful nutrients without blowing your calorie budget. On a cut, stick to 1 oz. On a bulk, 2 oz daily fits easily.
Are walnuts or almonds healthier?
Both are excellent. Walnuts (654 cal per 100g) have more polyunsaturated fat and omega-3s. Almonds (614 cal per 100g) have more protein (21g vs 15.2g), more fiber (10.3g vs 6.7g), and more vitamin E. For omega-3 intake, choose walnuts. For protein and fiber, choose almonds. Eating both is ideal.
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