A CLEARER WAY TO READ THE LABEL

What goes into a net carb?

Net carbs are a food-planning estimate, not a regulated nutrient measurement. The number depends on the label convention and deductions you choose. Our calculators make that arithmetic visible.

1. Start with the right carbohydrate number

On US and Canadian labels, total carbohydrate includes fiber. The basic calculation here is total carbohydrate minus dietary fiber. Use total carbohydrate, not the “total sugars” or “added sugars” line.

On UK/EU labels, the carbohydrate line already excludes fiber. Choose UK/EU mode to avoid subtracting it twice. Polyols may still be included. When mixing ingredients from different labeling systems, calculate each ingredient separately first.

2. Treat sweeteners carefully

Our default counts all sugar alcohols. In the optional settings, you can deduct 50% or 100% of the entered sugar-alcohol amount. These are transparent accounting choices, not precise predictions of absorption. Different polyols and individuals behave differently; a full deduction can underestimate usable carbohydrate.

Allulose has its own field. Enter only an amount included in the carbohydrate total, and do not also enter it as a sugar alcohol. The tool subtracts the entered allulose amount fully for its net-carb estimate. FDA guidance keeps allulose within total carbohydrate while allowing different treatment for sugar and calorie declarations.

3. Match the amount you eat

For a serving-based label, multiply the adjusted carbs by servings eaten. For a label stated per 100 g, multiply by your portion weight divided by 100. For example, 12 g total carbs minus 5 g fiber gives 7 g net carbs per serving; two servings give 14 g.

What the other tools do

• Meal calculator: sums each food’s net carbs multiplied by its servings, then compares that sum with your chosen daily target.
• Recipe calculator: subtracts applicable fiber from the whole batch and divides it into equal portions. It does not apply sweetener deductions.
• Macro calculator: uses 4 kcal/g for net carbs and protein and 9 kcal/g for fat to convert your chosen targets. Real food energy can differ.

Know the limits

Label rounding, ingredient variation, digestion, and preparation introduce uncertainty. Results are displayed to at most two decimal places, but extra digits do not make the underlying label data more precise. No result guarantees ketosis or predicts blood glucose.

The American Diabetes Association does not recognize “net carbs” as a standardized term and recommends using total carbohydrate for diabetes management. These tools must not be used to calculate insulin doses or change medication. Follow your care team’s plan.

Sources & further reading

• American Diabetes Association: Get to Know Carbs
• FDA: Allulose labeling guidance
• Diabetes UK: Understanding food labels

Methodology reviewed September 10, 2026.