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Flax Seeds Nutrition Facts: Are Flax Seeds Good for You?
Flax seeds provide high amounts of many nutrients, including dietary fiber, magnesium, copper, manganese, and thiamin. A 100-gram serving contains 534 calories and about 42 grams of fat, most of which is polyunsaturated. While they offer significant amounts of certain vitamins and minerals, their contribution to a healthy diet depends on portion size and what else you eat.
Per 100 g · Seeds, flaxseed
What stands out in flax seeds
- Very high in fiber. A 100-gram serving of flax seeds contains 27.3 grams of dietary fiber. This amount supplies 98% of the Daily Value for fiber.
- High in several minerals. Flax seeds are high in multiple minerals. A 100-gram portion provides 93% of the Daily Value for magnesium, 136% for copper, and 108% for manganese.
- Source of polyunsaturated fat. Flax seeds contain 42.2 grams of total fat per 100 grams. Of this, the majority, 28.7 grams, is polyunsaturated fat, with 7.5 grams of monounsaturated fat and 3.7 grams of saturated fat.
- High in thiamin (B1). A 100-gram serving of flax seeds offers 1.6 mg of thiamin. This provides 137% of the Daily Value for this B vitamin.
What to keep in mind
- A 100-gram serving of flax seeds has 534 calories and 54% of the Daily Value for total fat. While low in sodium and cholesterol-free, portion sizes are a key consideration due to their calorie and fat content.
Flax Seeds nutrition facts per 100 g
| Nutrient | Per 100 g | % DV |
|---|---|---|
| Calories | 534 kcal | – |
| Protein | 18.3 g | 37% |
| Total fat | 42.2 g | 54% |
| Saturated fat | 3.7 g | 18% |
| Monounsaturated fat | 7.5 g | – |
| Polyunsaturated fat | 28.7 g | – |
| Cholesterol | 0 mg | 0% |
| Carbohydrate | 28.9 g | 11% |
| Dietary fiber | 27.3 g | 98% |
| Total sugars | 1.6 g | – |
| Water | 7 g | – |
| Sodium | 30 mg | 1% |
| Nutrient | Per 100 g | % DV |
|---|---|---|
| Potassium | 813 mg | 17% |
| Calcium | 255 mg | 20% |
| Iron | 5.7 mg | 32% |
| Magnesium | 392 mg | 93% |
| Phosphorus | 642 mg | 51% |
| Zinc | 4.3 mg | 39% |
| Copper | 1.2 mg | 136% |
| Manganese | 2.5 mg | 108% |
| Selenium | 25.4 mcg | 46% |
| Vitamin A (RAE) | 0 mcg | 0% |
| Vitamin C | 0.6 mg | 1% |
| Vitamin D | 0 mcg | 0% |
| Vitamin E | 0.31 mg | 2% |
| Vitamin K | 4.3 mcg | 4% |
| Thiamin (B1) | 1.6 mg | 137% |
| Riboflavin (B2) | 0.16 mg | 12% |
| Niacin (B3) | 3.1 mg | 19% |
| Vitamin B6 | 0.47 mg | 28% |
| Folate (DFE) | 87 mcg | 22% |
| Vitamin B12 | 0 mcg | 0% |
| Choline | 78.7 mg | 14% |
% Daily Value uses the FDA Daily Values for adults and children 4 years and older. Highlighted rows are 20% DV or more per 100 g. A dash means no Daily Value is set.
Flax Seeds by portion
The nutrition values change significantly with portion size. A tablespoon of whole flax seeds (10 grams) provides 55 calories, 4.3 grams of fat, and 2.8 grams of fiber. A tablespoon of ground flax seeds, which weighs less at 7 grams, contains 37 calories, 3 grams of fat, and 1.9 grams of fiber. A much larger portion, one cup of whole seeds, contains 897 calories and about 71 grams of fat.
| USDA portion | Weight | Calories | Protein | Carbs | Fiber | Fat |
|---|---|---|---|---|---|---|
| 1 tbsp, whole | 10 g | 55 | 1.9 g | 3 g | 2.8 g | 4.3 g |
| 1 cup, whole | 168 g | 897 | 30.7 g | 48.6 g | 45.9 g | 70.9 g |
| 1 tbsp, ground | 7 g | 37 | 1.3 g | 2 g | 1.9 g | 3 g |
| 1 tsp, whole | 3.4 g | 18 | 0.6 g | 1 g | 0.9 g | 1.4 g |
| 1 tsp, ground | 2.5 g | 13 | 0.5 g | 0.7 g | 0.7 g | 1.1 g |
How flax seeds compares with other nuts and seeds
Among 16 nuts and seeds on this site, flax seeds rank second highest for dietary fiber (27.3 g per 100 g) and third highest for carbohydrates (28.9 g). They rank lower for total fat and calories, at 15th out of 16. Compared to similar foods per 100 g, flax seeds have less fat than hemp seeds (49 g) and pumpkin seeds (49 g). However, they contain significantly more fiber than cashews (3.3 g), hemp seeds (4.0 g), pistachios (10.6 g), and pumpkin seeds (6.0 g).
| Per 100 g | Calories | Protein | Carbs | Fiber | Fat |
|---|---|---|---|---|---|
| Flax Seeds | 534 | 18.3 g | 28.9 g | 27.3 g | 42.2 g |
| Cashews | 553 | 18.2 g | 30.2 g | 3.3 g | 43.9 g |
| Hemp Seeds | 553 | 31.6 g | 8.7 g | 4 g | 48.8 g |
| Pistachios | 560 | 20.2 g | 27.2 g | 10.6 g | 45.3 g |
| Pumpkin Seeds | 559 | 30.2 g | 10.7 g | 6 g | 49 g |
Quick answers
How many calories are in a tablespoon of flax seeds?
A tablespoon of whole flax seeds has 55 calories. A tablespoon of ground flax seeds contains 37 calories.
How much protein is in flax seeds?
A 100-gram serving of flax seeds contains 18.3 grams of protein, which is 37% of the Daily Value. A tablespoon of whole flax seeds has 1.9 grams of protein.
Are flax seeds low in sugar?
Yes, the data shows flax seeds are very low in sugar. A 100-gram serving contains 1.6 grams of total sugars, and a tablespoon of whole seeds has just 0.2 grams.
When to talk to a doctor or dietitian
- At 813 mg of potassium per 100 g, flax seeds is worth discussing if you have kidney disease or take a medicine that raises potassium levels; your doctor or a renal dietitian can tell you how much fits your plan.
- This page describes nutrient content, not medical advice. If a health condition, medicine or pregnancy affects what you eat, a doctor or registered dietitian can tell you how flax seeds fits your situation.
Last updated October 21, 2026