Fibre passes through the gut largely undigested, and most sugar alcohols are only partly absorbed, so they have a smaller effect on blood sugar. On US labels fibre is included in total carbohydrate; in the EU and UK it is listed separately, so check your label.
How to use the Net Carbs Calculator
- Total carbohydrates
- Dietary fibre
- Erythritol or allulose
- Other sugar alcohols
- Count other sugar alcohols as
- Label style
- Servings
Results update as you type, and every field accepts the units shown in its menu.
How it works
Read the nutrition label for one serving, enter total carbohydrate, fibre and sugar alcohols, and choose how to count other sugar alcohols. Multiply by the number of servings you eat.
Inputs explained
| Field | What to enter |
|---|---|
| Total carbohydrates | In g |
| Dietary fibre | In g |
| Erythritol or allulose | In g |
| Other sugar alcohols | In g |
| Count other sugar alcohols as | Choose one: Half (subtract 50%), Zero (subtract 100%), Full carbs (subtract 0%) |
| Label style | Choose one: US (fibre included in total), EU/UK (fibre listed separately) |
| Servings | A number |
What each result means
- Net carbs for your servings = [Net carbs per serving]×[Servings]
- Calories from net carbs = [Net carbs for your servings]×4
Example values
How the main result changes when Total carbohydrates changes and everything else stays at the example values above:
| Total carbohydrates (g) | Net carbs per serving (g) |
|---|---|
| 15 | 4 |
| 22.5 | 11.5 |
| 30 | 19 |
| 37.5 | 26.5 |
| 45 | 34 |
| 60 | 49 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Net carbs = total carbs − fibre − erythritol/allulose − sugar alcohols × factor
(factor 0.5 for maltitol, sorbitol and similar, or 1 to subtract fully)
Worked example
Inputs — Total carbohydrates: 30 g; Dietary fibre: 8 g; Erythritol or allulose: 0 g; Other sugar alcohols: 6 g; Count other sugar alcohols as: Half (subtract 50%); Label style: US (fibre included in total); Servings: 1.
Results — Net carbs per serving = 19 g; Net carbs for your servings = 19 g; Calories from net carbs = 76 kcal.
Key terms
- Sugar alcohols
- Sweeteners such as erythritol, xylitol and maltitol that are partly absorbed.
Frequently asked questions
Are net carbs official?
No – the term is not regulated by the FDA, but it is widely used on low-carb diets.
Why subtract only half of some sugar alcohols?
Maltitol and sorbitol are partly absorbed and do raise blood sugar somewhat.
How many net carbs on keto?
Usually under 20–50 g a day.