Last updated October 5, 2026 · Report an error
Net carbs is standard nutrition-label arithmetic used by low-carb and ketogenic diet trackers: net carbs = total carbohydrates - fiber - (sugar alcohols x 0.5), using the common half-count convention for sugar alcohols. This is simple label arithmetic, not medical or nutritional advice — individual sugar alcohols vary in how much they affect blood sugar, so consult a doctor or registered dietitian for guidance specific to a medical condition such as diabetes.
How it works
Enter total carbohydrates, fiber, and (optionally) sugar alcohols from a nutrition label. The tool subtracts fiber and half of the sugar alcohols from total carbs.
- Enter total carbohydrates (g).
- Enter dietary fiber (g).
- Enter sugar alcohols (g, optional).
- Click Calculate to see your results.
Examples
A label showing 30g carbs, 8g fiber, 5g sugar alcohols
Net carbs = 30 - 8 - (5 x 0.5) = 19.5g.
Who should use it
- Tracking net carbs for a low-carb or ketogenic diet.
- Comparing packaged foods for carb content beyond the raw total-carbs number.
Industry applications
- Nutrition tracking and dieting
- Food product labeling reference
Advantages
- Simple, quick arithmetic matching common low-carb tracking conventions.
- Works directly from standard nutrition label numbers.
Limitations
- The half-count convention is a simplification — actual absorption varies by specific sugar alcohol.
- Not an officially regulated nutrition-label term in most countries.
Common mistakes to avoid
- Applying the half-count convention uniformly to all sugar alcohols, when some (like erythritol) may have an even smaller real effect on blood sugar.
- Forgetting to subtract fiber, which many nutrition trackers already exclude from "net" carb counts.
Best practices
- For a specific medical condition like diabetes, discuss individual sugar alcohol effects with a doctor or registered dietitian rather than relying solely on the standard half-count convention.
Tips
- Check whether a specific sugar alcohol (like erythritol) has published guidance suggesting it should be counted as 0g rather than the standard half-count.