Net Carbs Calculator
Fibre passes through undigested and does not raise blood sugar. Sugar alcohols vary, but roughly half of them are absorbed. What remains after subtracting both is the carbohydrate that actually reaches you.
Your numbers
Net carbs
34.5g
Calories
138kcal
Formula
Net carbs = Carbs − Fibre − Sugar alcohols ÷ 2
Erythritol is barely absorbed while maltitol is largely absorbed. If the label names the type, adjust the figure accordingly.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Carbs (g)Grams of carbohydrate for the day; each gram is 4 kcal. | 45 | 0 and up |
| Fibre (g)Daily fibre; the reference is 14 g per 1,000 kcal. | 8 | 0 and up |
| Sugar alcohols (g)Sweeteners like erythritol or maltitol; roughly half is absorbed. | 5 | 0 and up |
Step by step
Quick reference table
Results when only Carbs (g) changes and everything else stays put.
| Carbs (g) | Net carbs (g) | Calories (kcal) |
|---|---|---|
| 22.5 | 12 | 48 |
| 33.8 | 23.3 | 93 |
| 45 | 34.5 | 138 |
| 67.5 | 57 | 228 |
| 90 | 79.5 | 318 |
What each result means
| Result | At default values |
|---|---|
| Net carbs (g)The carbohydrate actually absorbed, after fibre and sugar alcohols. | 34.5 |
| Calories (kcal)Energy, in kilocalories. | 138 |
Common mistakes
Erythritol is barely absorbed while maltitol is largely absorbed. If the label names the type, adjust the figure accordingly.
Glossary
- Carbs
- Grams of carbohydrate for the day; each gram is 4 kcal.
- Fibre
- Daily fibre; the reference is 14 g per 1,000 kcal.
- Sugar alcohols
- Sweeteners like erythritol or maltitol; roughly half is absorbed.
- Net carbs
- The carbohydrate actually absorbed, after fibre and sugar alcohols.
- Calories
- Energy, in kilocalories.
Frequently asked questions
Q. How is Net Carbs Calculator calculated?
Net carbs = Carbs − Fibre − Sugar alcohols ÷ 2 — Fibre passes through undigested and does not raise blood sugar. Sugar alcohols vary, but roughly half of them are absorbed. What remains after subtracting both is the carbohydrate that actually reaches you.
Q. Can you walk through an example?
With Carbs 45g, Fibre 8g, Sugar alcohols 5g, the answer is Net carbs 34.5g.
Q. What do I need to enter?
Enter Carbs, Fibre, Sugar alcohols. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Carbs (g) moves the answer to Carbs (g) 22.5 → Net carbs (g) 12 and Carbs (g) 90 → Net carbs (g) 79.5. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Erythritol is barely absorbed while maltitol is largely absorbed. If the label names the type, adjust the figure accordingly.
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These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.