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Net Carb Estimate Calculator

Use values from the same serving or 100 g column on a nutrition label. Total Carbohydrate is the unambiguous US label value; “net carbs” is an informal estimate, not a nutrient the FDA defines or requires. This calculator subtracts only the adjustments you choose.

Enter one label basis

Label formatChoose the format printed on the package. Changing formats clears every entered value.
Enter the numeric value for one serving or 100 g. For a less-than declaration, follow the rounding note above. Accepted range: 0 to 10,000 g.
Copy the fiber value from the same label basis. It is not deducted unless you select the checkbox below.
Use zero or leave blank if the label does not provide this amount.
Enter only the gram adjustment required by a method you follow, up to the amount at left. There is no universal percentage for every polyol; otherwise leave this at zero.
Enter a value only when the manufacturer identifies allulose for the same serving.
Enter an adjustment only when you have a defined counting method. Otherwise leave it at zero.

No estimate yet

Choose the label format, enter its values, and select Calculate estimate.

The calculator does not create a result until you submit the form.

How the estimate treats each label

US Nutrition Facts

FDA’s Total Carbohydrate value includes dietary fiber, sugar alcohols, and allulose. This calculator keeps that total visible and makes every deduction optional. Sugar alcohols can differ in absorption and metabolism, and a label may combine several compounds, so the calculator does not apply a blanket percentage.

FDA’s current allulose guidance keeps allulose in Total Carbohydrate while allowing manufacturers to exclude it from Total Sugars and Added Sugars. Enter allulose only when the manufacturer identifies the amount.

EU or UK-style nutrition declarations

These declarations list carbohydrate and fibre separately. Fibre is excluded from Carbohydrate by definition, even when the optional Fibre row is absent. This calculator never deducts it again. Polyols may appear beneath carbohydrate; any polyol adjustment remains your explicit choice.

Label rounding and incomplete voluntary fields can make the components look inconsistent. Use values from one serving or one 100 g column, and do not guess an unlisted component. A less-than declaration is an interval, so the calculator cannot recover its exact value.

Official label sources

Frequently asked questions

What does "net carbs" mean in this calculator?

"Net carbs" is an informal estimate, not a nutrient that the FDA defines or requires on a Nutrition Facts label. The estimate starts with the label carbohydrate value and subtracts only the adjustments you select.

Why does the label format matter?

US Total Carbohydrate includes dietary fiber and sugar alcohols. EU and UK-style declarations list fibre separately from carbohydrate, so subtracting fibre from that carbohydrate value would count the same difference twice.

Why is there no fixed sugar-alcohol percentage?

Sugar alcohols differ in how they are absorbed and metabolized, and a label can group more than one compound together. No single percentage is reliable for every product. Enter only an adjustment from a defined counting method; otherwise leave it at zero and use the label carbohydrate value.

How does the calculator handle allulose?

FDA guidance keeps allulose within Total Carbohydrate while allowing it to be excluded from Total Sugars and Added Sugars. If a US product identifies its allulose amount, you can enter a separate adjustment; the calculator does not assume one.

What if a US label says "less than 1 g"?

A "less than 1 g" Total Carbohydrate declaration represents 0.5 g to less than 1 g under FDA rounding, so the exact amount cannot be recovered from the label. Do not enter the less-than symbol as a numeric value. Enter a numeric assumption only when your counting method supplies one, and treat the estimate as assumption-based.