Net Carbs Calculator

“Net carbs” is used for different carbohydrate calculations. Here the output is explicitly declared-label arithmetic: subtract fiber only when the entered carbohydrate total includes it; otherwise keep the carbohydrate amount unchanged. Polyols remain included.

The page language does not identify the food label’s convention. A translated page can be used with an imported product, so choose the basis shown by the actual label.

1. Use carbohydrate, fiber and polyol grams for the same portion or per-100-g quantity.
2. Confirm whether the declared carbohydrate includes or excludes fiber.
3. Select that basis explicitly before calculating.
4. For an inclusive total, subtract fiber once. For an excluded total, subtract none.
5. Retain polyols; no glycemic deduction factor is applied.

Worked comparison: 20 g carbohydrate, 5 g fiber and 2 g polyols gives 15 g when carbohydrate includes fiber and 20 g when fiber is already excluded. The 2 g polyols are retained in both results.

Inclusive consistency requires fiber plus polyols to fit inside carbohydrate. With an excluded basis, polyols must fit inside carbohydrate but separately declared fiber may exceed it. The form rejects inconsistent values rather than clamping the result.

Fiber is a separate label component whose inclusion in the carbohydrate total depends on the labeling convention. FDA nutrition labeling rule, 21 CFR 101.9(c)(6) uses a total-carbohydrate calculation including dietary fiber. In the EU, Annex I of Regulation (EU) 1169/2011 defines carbohydrate separately from fiber. Checked September 30, 2026.

A label that already excludes fiber must not have fiber subtracted again. This subtraction choice is label interpretation, not a measurement of digestion or individual blood-glucose response.

Polyols (sugar alcohols) include erythritol, xylitol, sorbitol and maltitol. FDA’s sugar-alcohol factsheet (October 2021) describes incomplete absorption and smaller glucose changes than other carbohydrates, not a uniform zero effect. An energy factor does not establish a glycemic subtraction percentage. Checked September 30, 2026.

Steviol glycosides and monk fruit extracts are high-intensity sweeteners, not sugar alcohols. Ingredient names alone cannot establish grams to deduct. See FDA high-intensity sweeteners, checked September 30, 2026.

This calculator retains all entered polyols. No 25%, 50%, 75% or 100% automatic deduction is used.

Declared-label arithmetic does not predict ketosis, fat loss, insulin requirements or the effect of a meal on blood glucose. The output is not a personal low-carbohydrate allowance and is not assigned a keto-suitability grade.

When comparing foods, keep both the original declared carbohydrate and the selected basis in your record. A comparison is meaningful only when portions and label conventions are consistent.

Check whether values refer to a serving, 100 g or 100 ml, then enter all components on that same basis. Do not combine 100-g carbohydrate with serving-size fiber.

US total carbohydrate includes fiber. EU carbohydrate excludes fiber and includes polyols; fiber is a separately declared component. European Commission nutrition-label guidance explains that fiber and polyol declarations are voluntary additions to the mandatory declaration. Checked September 30, 2026.

If the basis is unclear, verify it before calculating. If a polyol amount is not declared, leaving 0 means no amount was entered; it is not proof that the food contains none. Ingredient names do not give their quantity.