Walnuts are one of the most calorie-dense nuts you can eat, delivering around 650 kcal per 100 g along with healthy fats, protein, and fiber. If you are tracking your daily intake, counting calories for walnuts can be tricky because portion sizes vary widely—from a small handful to a cup of chopped nuts. This walnut calories per 100g calculator takes the guesswork out of it, converting any amount, whether grams, ounces, cups, or walnut halves, into a precise calorie count using standard nutrition data.
Simply enter the amount of walnuts you plan to eat, choose your preferred unit, and select the walnut variety if you know it. An optional macronutrient breakdown shows fat, protein, carbohydrates, fiber, and sugars for your exact portion. Whether you're meal prepping, diet planning, or just curious about your snack, this tool is designed to give you a fast and dependable answer in seconds.
🥜 Walnut Calorie Calculator
Enter an amount to calculate calories and (optionally) the full nutrition profile for walnuts.
How to Use This Calculator
Start by entering the number of walnuts you want in the field, then choose the unit that matches how you measure them: grams, ounces, cups of walnut halves, cups of chopped nuts, or the number of individual halves. If you know whether you're eating English (California) or black walnuts, select the correct variety for more accurate results. Press Calculate to see the calorie total instantly.
For anyone who tracks macros or follows a specific diet, tick the “Show full macronutrient breakdown” box. The calculator will then display not just calories, but also fat, protein, carbohydrates, fiber, and sugars for your exact portion. If you want to clear the form and start over, use the Reset button.
How the Calculation Works
Walnuts are one of the most energy-dense foods, so the math is straightforward. The calculator first converts your chosen unit into grams. Then it applies the calorie density of the selected walnut type:
Calories = grams of walnuts × (kcal per 100 g / 100)
Example: 45 g of English walnuts = 45 × 6.54 = 294 kcal.
The standard nutritional reference values are derived from USDA FoodData Central. English walnuts contain roughly 654 kcal per 100 g; black walnuts contain about 619 kcal per 100 g. The macronutrient breakdowns also follow USDA data, so you can confidently use these numbers for meal planning or fitness tracking.
Walnut Nutrition at a Glance
Here is the per-100g nutritional profile for the two common walnut varieties used in this tool:
| Nutrient | English walnut (per 100 g) | Black walnut (per 100 g) |
|---|---|---|
| Calories | 654 kcal | 619 kcal |
| Fat | 65.2 g | 59.3 g |
| Protein | 15.2 g | 24.1 g |
| Carbohydrates | 13.7 g | 9.9 g |
| Fiber | 6.7 g | 6.8 g |
| Sugars | 2.6 g | 1.1 g |
As you can see, the two types differ mainly in protein and fat content, which explains why the calorie counts are not identical.
Why Portion Size Matters
A typical serving of walnuts is 1 ounce (28.35 g), which is about 14 halves. That serving supplies roughly 185 kcal and about 18 g of fat. Because walnuts are so calorie-dense, it's easy to eat 100 g without realizing it—about 1 cup of halves or just over a handful. On a 2,000 kcal daily target, 100 g of walnuts represents nearly one-third of your calories, so portion awareness is key.
Tip: pre-portion your walnut snacks into small bags or containers. A one-ounce handful is a great source of omega-3 fats and protein without blowing your daily calorie budget.
Common Mistakes to Avoid
Weighing walnuts in the shell: shelled walnuts weigh about half as much as unshelled ones. If you weigh whole walnuts, you will overestimate the edible portion by a large margin. This calculator assumes shelled, edible kernels.
Another common error is confusing chopped and half measurements. One cup of walnut halves weighs about 100 g, while one cup of chopped walnuts weighs about 120 g. When a recipe calls for chopped walnuts, using halves and assuming 100 g will underestimate the calories by roughly 20%. Always match your unit to the physical form you're using.
Also be aware that flavored or glazed walnuts—honey-roasted, candied, or coated in chocolate—add sugar and sometimes oil, raising the calorie content well above plain walnuts. Check the package label if you're eating anything other than raw, dry-toasted, or lightly salted nuts.
Frequently Asked Questions
How many walnuts are in 100 g?
Roughly 14 to 16 walnut halves make up 28 g (1 oz), so 100 g corresponds to approximately 50 to 57 halves, or about 25 to 28 whole shelled walnuts. The exact number depends on the size of the nuts, which vary by variety and crop.
Are walnuts good for weight loss despite being high in calories?
Yes, in moderation. Walnuts are rich in polyunsaturated fats, fiber, and protein, all of which promote satiety. Studies suggest that including a moderate serving of nuts (about 1 oz per day) can support weight management without leading to weight gain, as long as your total calorie intake stays within your goals.
Do toasted walnuts have more calories than raw ones?
Dry roasting does not add calories unless oil or butter is used. However, dry-toasted walnuts lose a bit of water, so their calories per gram may appear slightly higher. For practical purposes, the difference is small, and the calorie values in this calculator remain a good estimate for both raw and dry-toasted commercial walnuts.
Can I use this calculator for other nuts?
No—this tool uses walnut-specific values. Each nut has its own calorie density and macronutrient profile. If you're planning mixed-nut snacks, calculate each nut separately and add the results, or check the nutrition label on your mixed-nut package.