How do you calculate net carbs?

Net Carbs = Total Carbohydrates − Dietary Fiber − Sugar Alcohols. Fiber is indigestible and does not raise blood sugar. Sugar alcohols vary — erythritol has 0% impact while maltitol has ~50% impact on blood glucose.

Do all sugar alcohols count as net carbs?

No. Different sugar alcohols have different glycemic impacts: Erythritol = 0% (fully subtract), Xylitol = 60% impact (subtract 40%), Maltitol = 50% impact (subtract 50%), Sorbitol = 75% impact (subtract 25%).

What is the difference between net carbs and total carbs?

Total carbs include all carbohydrates: sugar, starch, fiber, and sugar alcohols. Net carbs (also called effective carbs or digestible carbs) exclude fiber and adjust for sugar alcohols since these do not significantly raise blood glucose or insulin.

How many net carbs per day for keto?

For strict ketosis, most people stay under 20g net carbs per day. A moderate keto approach allows 20–50g. Some active individuals can maintain ketosis at up to 50g net carbs depending on their metabolism and exercise level.

Net Carbs Calculator

Calculate net carbs by subtracting fiber and sugar alcohols from total carbohydrates. Includes food label reader, meal tracker, and sugar alcohol impact factors for keto dieting.

Total Carbohydrates ?

Dietary Fiber

Sugar Alcohols

Net Carbs

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Effective Carbs (half SA) —

Keto-Friendly per Serving? —

Extended More scenarios, charts & detailed breakdown ▾

Total Carbs

Fiber

Sugar Alcohols

Net Carbs

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Effective Carbs —

Keto-Friendly? —

Professional Full parameters & maximum detail ▾

Total Carbohydrates

Dietary Fiber

Sugar Alcohol Type

Sugar Alcohols Amount

Daily Net Carb Budget ?

Net Carbs Already Eaten Today

Net Carb Analysis

Sugar Alcohol Impact Factor —

Net Carbs (this food) —

Keto Assessment

Glycemic Impact Estimate —

Keto-Friendly Verdict —

Daily Budget

Daily Budget Remaining —

How to Use This Calculator

Enter Total Carbohydrates, Dietary Fiber, and Sugar Alcohols from the nutrition label.
Net carbs and effective carbs are calculated instantly.
Use the Food Label tab to enter a full nutrition panel including servings.
Use the Meal Tracker tab to sum net carbs from 3 different foods.
Use the Professional tab to select specific sugar alcohol types and check your remaining daily carb budget.

Formula

Net Carbs = Total Carbs − Fiber − Sugar Alcohols
Effective Carbs = Total Carbs − Fiber − (Sugar Alcohols × 0.5)
For specific sugar alcohols: Erythritol factor = 0%, Xylitol = 60%, Maltitol = 50%, Sorbitol = 75%

Example

Example: Nutrition label shows 30g total carbs, 8g fiber, 5g erythritol (sugar alcohol). Net Carbs = 30 − 8 − 5 = 17g. Effective Carbs = 30 − 8 − (5 × 0.5) = 19.5g.

Frequently Asked Questions

Net Carbs = Total Carbohydrates − Dietary Fiber − Sugar Alcohols. Fiber is indigestible and does not raise blood sugar. Sugar alcohols vary — erythritol has 0% impact while maltitol has ~50% impact on blood glucose.
No. Different sugar alcohols have different glycemic impacts: Erythritol = 0% (fully subtract), Xylitol = 60% impact (subtract 40%), Maltitol = 50% impact (subtract 50%), Sorbitol = 75% impact (subtract 25%).
Total carbs include all carbohydrates: sugar, starch, fiber, and sugar alcohols. Net carbs (also called effective carbs or digestible carbs) exclude fiber and adjust for sugar alcohols since these do not significantly raise blood glucose or insulin.
For strict ketosis, most people stay under 20g net carbs per day. A moderate keto approach allows 20–50g. Some active individuals can maintain ketosis at up to 50g net carbs depending on their metabolism and exercise level.

Related Calculators

Sources & References (5) ▾

Institute of Medicine (NASEM) — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005) — National Academies Press
Livesey G — Health potential of polyols as sugar replacers, with emphasis on low glycaemic properties. Nutr Res Rev. 2003;16(2):163-191 — Nutrition Research Reviews
Westman EC et al. — Low-carbohydrate nutrition and metabolism. Am J Clin Nutr. 2007;86(2):276-284 — American Journal of Clinical Nutrition
FDA — Guidance for Industry: Food Labeling — Total Carbohydrates and Dietary Fiber — FDA
Nettleton JA et al. — Dietary patterns and incident cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis. Am J Clin Nutr. 2009;90(3):647-654 — American Journal of Clinical Nutrition