ConverterHub

Net Carbs Calculator

Find the digestible carbs that actually count

Result

11.0 g

How it is calculated

The tool uses net = total_carbs − fiber − sugar_alcohol / 2, with all three amounts in grams per serving, taken from the nutrition label. Only half of the sugar alcohols are subtracted, which is a rule of thumb rather than an exact figure, because different polyols are absorbed to different degrees. All three fields must be filled in (enter 0 where a food has none) and none can be negative. If the subtraction goes below zero, the result is shown as 0.0 g. The result is rounded to one decimal. Note that labelling rules differ by country: in some places the printed carbohydrate figure already excludes fibre.

Worked example

A protein bar label lists 24 g total carbohydrate, 9 g dietary fibre and 8 g sugar alcohols. Half of the sugar alcohols: 8 / 2 = 4 g. Subtract fibre and that half from the total: 24 − 9 − 4 = 11.0 g of net carbs per bar. If the label had shown only 5 g total carbohydrate with the same fibre and sugar alcohols, the result would be 0.0 g, not a negative number.

Try this example →

Common mistakes

  • Subtracting all of the sugar alcohols instead of half, which understates the net carbs; this tool subtracts half.
  • Using the carbohydrate figure from a label that already excludes fibre, so fibre gets subtracted twice.
  • Entering per-100 g values for fibre but per-serving values for total carbohydrate.
  • Leaving a field empty rather than typing 0; all three inputs are required.
  • Treating all sugar alcohols alike; the half rule is an average and not an exact value for each sweetener.

About this calculator

Net carbs are calculated as total carbohydrates minus fiber minus half of sugar alcohols (net = total − fiber − sugar alcohols/2). Fiber passes through the digestive system largely unmetabolized, and most sugar alcohols like erythritol or xylitol are only partially absorbed, so both are stripped out — partially, in the case of sugar alcohols — to leave the carbs that actually raise blood glucose.

Followers of low-carb and ketogenic diets track this number instead of total carbs because it more closely predicts the metabolic and insulin response to a food, and it's the figure most keto meal plans and macro trackers budget against, especially useful for packaged foods where fiber and sugar alcohol content varies widely on the label.

Was this helpful?

You can pick up to 3 reactions.

Comments (0)

  • Be the first to comment.

Popular calculators

Loan Calculator

Monthly payment, total interest and full amortization schedule.

Percentage Calculator

Percent change, percent of, and ratio calculations.

Discount Calculator

Calculate final price, savings, and discount amount.

BMI Calculator

Body mass index from height and weight (metric or imperial).

Age Calculator

Compute your exact age in years, months and days from a birth date.

Compound Interest Calculator

Calculate the final amount and interest earned with compounding.

All Calculators