Net Carbs Calculator
Work out net carbs from a nutrition label: total carbohydrates minus fiber and sugar alcohols, per serving and for the servings you ate. Add your other foods to get a daily net carb total and compare it with your keto or low-carb limit.
Last updated:
Almost no impact on blood sugar: always fully subtracted
e.g. 20–25 g strict keto, 50 g low carb
How to use the Net Carbs Calculator
- Read the nutrition label and enter total carbohydrates, fiber and sugar alcohols per serving.
- Enter erythritol or allulose separately if listed.
- Set servings and choose how to count sugar alcohols.
- Add today's other foods as lines: name, carbs, fiber, sugar alcohols, servings.
- Compare the daily total with your limit and download the list.
Net carbs formula
Net carbs = total carbohydrates − dietary fiber − sugar alcohols
Conservative version: net carbs = total carbs − fiber − ½ × sugar alcohols (with erythritol and allulose still subtracted fully).
Example: sugar-free chocolate with 18 g carbs, 3 g fiber and 12 g maltitol → full method 18 − 3 − 12 = 3 g; half method 18 − 3 − 6 = 9 g net carbs.
Sugar alcohols and blood sugar
| Sweetener | Glycemic index (approx.) | Calories per gram (approx.) | Usual net carb treatment |
|---|---|---|---|
| Erythritol | 0 | 0–0.2 | Subtract fully |
| Allulose (rare sugar) | 0 | 0.2–0.4 | Subtract fully |
| Xylitol | 7–13 | 2.4 | Subtract (or half) |
| Sorbitol | ≈ 9 | 2.6 | Subtract half |
| Maltitol | ≈ 35–52 | 2.1–3 | Subtract half |
| Sugar (sucrose), for comparison | ≈ 65 | 4 | Not subtracted |
Net carbs in common foods
| Food | Total carbs | Fiber | Net carbs |
|---|---|---|---|
| Avocado (1 medium, ~200 g) | 17 g | 13.5 g | ≈ 3.5 g |
| Almonds (28 g / 1 oz) | 6 g | 3.5 g | ≈ 2.5 g |
| Broccoli (1 cup chopped, raw) | 6 g | 2.4 g | ≈ 3.6 g |
| Raspberries (1 cup) | 14.7 g | 8 g | ≈ 6.7 g |
| Apple (1 medium) | 25 g | 4.4 g | ≈ 20.6 g |
| White bread (1 slice) | 13 g | 0.6 g | ≈ 12.4 g |
Values are typical USDA-style figures; check your product's label for exact numbers.
Frequently asked questions
How do I calculate net carbs?
Net carbs = total carbohydrates − dietary fiber − sugar alcohols. For a bar with 20 g carbs, 8 g fiber and 4 g sugar alcohols: 20 − 8 − 4 = 8 g net carbs per serving.
Should I subtract all sugar alcohols?
Erythritol and allulose have almost no effect on blood sugar, so they are usually subtracted fully. Maltitol, sorbitol and some others are partly absorbed, so many people subtract only half of them for a more conservative count.
Are net carbs on EU or UK labels different?
Yes. In the EU, UK and Australia the carbohydrate figure already excludes fiber, so it is effectively net of fiber. Don't subtract fiber again; only subtract polyols (sugar alcohols) if they are listed.
How many net carbs on keto?
Strict ketogenic diets usually keep net carbs around 20–50 g per day, often starting at 20–25 g. Low-carb diets that are not ketogenic often allow 50–100 g per day.
Is 'net carbs' an official term?
No. The FDA does not define net carbs, so it is a calculation used by dieters and food makers. Total carbohydrates, fiber and sugar alcohols on the label are the regulated numbers.
Do net carbs affect calories?
Fiber and sugar alcohols still contain some calories (about 2 kcal/g for fiber and 0–3 kcal/g for sugar alcohols), so a low net carb food is not necessarily low in calories.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.