Can flax seeds fit a keto diet?

Fits only in a measured amount

Yes, but only in a measured amount: flax seeds can fit a keto diet.

1 cup weighs 168 g; it contains 19 g calculated net carbs. The nutrition figures for flax seeds come from ground flaxseed.

Check another amount

Values update from the same USDA record. They do not estimate a personal carb target or ketosis response.

Amount in grams

Listed source portion: 1 cup (168 g).

Calculated net carbs

19 g

Total carbohydrate

57.8 g

Dietary fiber

38.8 g

Editorial illustration of Flax seeds.

Nutrition facts for Flax seeds

Source-portion carb band: Higher net carbs per listed portion. The category is based only on calculated net carbs for the listed portion: 5 g or less, more than 5 g to 10 g, or more than 10 g. Your total intake, preparation, and clinical context can change how a food fits your own plan.

Nutrient	Per listed portion: 1 cup (168 g)	Per 100 g
Energy	916 kcal	545 kcal
Protein	30.2 g	18 g
Total fat	62.7 g	37.3 g
Saturated fat	5.5 g	3.3 g
Total carbohydrate	57.8 g	34.4 g
Dietary fiber	38.8 g	23.1 g
Calculated net carbs	19 g	11.3 g
Total sugars	2.6 g	1.6 g
Sodium	62.2 mg	37 mg
Potassium	1332.2 mg	793 mg

The table keeps the USDA basis separate from the selected portion.

1. Food formFlax seeds
2. USDA per-100 g basis11.3 g calculated net carbs
3. Selected source portion19 g calculated net carbs
4. Calculation boundaryPortion value is calculated from the cited 100 g record and portion weight

Explore this food category

Compare this form and portion with other records in nuts, seeds & legumes. The category hub explains why forms, preparation, and portions should not be treated as interchangeable.

For meal-level context, use the keto food list.

How the calculation works

Calculated net carbs = total carbohydrate − dietary fiber. For this USDA record, that is 34.4 g − 23.1 g = 11.3 g per 100 g. Net carbs is a planning convention used on this site; it is not a separate USDA nutrient field or a regulatory nutrition-label value. This calculation does not automatically subtract sugar alcohols.

For the underlying approach and its limitations, see how net carbs are explained and the net-carb calculator.

Food record and source

• USDA food description: Flax seeds
• FoodData Central ID: FDC ID 2707588
• Dataset: Survey (FNDDS) FNDDS 2021-2023 (2024-10-31)
• Record publication date: 10/31/2024
• Selected portion: 1 cup (168 g)

The nutrition values are reported by the USDA per 100 g. The per-portion column above is calculated from that value and the USDA portion weight; no household measure was invented for this page.

1. USDA FoodData Central, Survey (FNDDS) FNDDS 2021-2023 (2024-10-31), FDC ID 2707588. https://fdc.nal.usda.gov/food-search/?query=2707588, https://fdc.nal.usda.gov/fdc-datasets/FoodData_Central_survey_food_json_2024-10-31.zip

Compare related foods

• Dried lentils cooked with no added fat — Compare another food in the nuts seeds legumes whole food group.
• Boiled peanuts — Compare another food in the nuts seeds legumes whole food group.
• Soy nuts — Compare another food in the nuts seeds legumes whole food group.

Browse all Food Database entries or start with the keto food list for practical meal-planning context.

Frequently Asked Questions

Can flax seeds fit a keto diet?

Flax seeds fit a keto diet only in a measured amount. 1 cup (168 g) contains 19 g calculated net carbs.

How many net carbs are in Flax seeds?

The listed 1 cup (168 g) has 19 g calculated net carbs. Per 100 g, the record has 11.3 g calculated net carbs.

How are net carbs calculated for Flax seeds?

247-Keto calculates net carbs as total carbohydrate minus dietary fiber, capped at zero. For this record, that is 34.4 g total carbohydrate minus 23.1 g fiber per 100 g. Sugar alcohols are not subtracted by this calculation.

Where do these Flax seeds nutrition facts come from?

The values come from USDA FoodData Central's Survey (FNDDS) FNDDS 2021-2023 (2024-10-31) release, FDC ID 2707588. The page preserves the listed food description and portion weight so the comparison is traceable.

Article history

1. September 11, 2026Updated after final factual and editorial review
2. August 24, 2026First published