How to Read Nutrition Labels for Carbs and Sugar
Nutrition labels contain the information you need to track carbs, but they are not always laid out in an obvious way. This guide explains what each line means and what to look at first.
Start with the serving size
The serving size is printed at the top of the label, before the calorie count. All nutrient values on the label apply to that serving size, not the whole packet. If a serving is 30g but you eat 60g, every number doubles. This is the most common source of confusion on labels.
Total Carbohydrates
Total Carbohydrates includes all forms of carbohydrate in the food: starches, sugars and dietary fiber. This is the number to watch when tracking total carb intake. It is listed in grams per serving.
Sugars (a subset, not an addition)
Sugars are listed as a sub-item under Total Carbohydrates, indented on most labels. They are part of the total carb number, not in addition to it. If a food has 20g of total carbs and 15g of sugars, the 15g of sugar is included within the 20g total.
Dietary Fiber and net carbs
Dietary fiber is also a sub-item under Total Carbohydrates. Because fiber is not digested and does not raise blood glucose, some people calculate net carbs by subtracting fiber from total carbs. Net carbs = Total Carbohydrates minus Dietary Fiber. This calculation is not an official regulated figure; it is a practical tool used in low-carb frameworks like keto.
Added Sugars
Many labels now show Added Sugars as a separate line under Sugars. Added sugars are sugars that were not present naturally in the food but were added during processing (table sugar, syrups, sweeteners). They are part of the total sugars number.
Sugar alcohols
Some products, especially low-carb snacks, sweetened with erythritol, xylitol or similar. These appear under Total Carbohydrates as Sugar Alcohols. Some low-carb frameworks subtract them partially (or fully, in the case of erythritol) when calculating net carbs, as they have minimal effect on blood glucose for most people.
If you are managing diabetes, on medication that affects blood glucose, or under medical supervision, involve your doctor in any decisions about how to track carbohydrates. This article is general information, not medical advice.
No Carbs Challenge helps you track your daily carb and sugar intake. For more on what counts as a hidden carb source, see the guide to hidden sugars in everyday foods.
Common questions
- What is the difference between total carbs and net carbs?
- Total carbs include everything: starches, sugars and fiber. Net carbs are calculated by subtracting dietary fiber (and sometimes sugar alcohols) from total carbs. Net carbs is not an official regulated figure but is widely used in low-carb and keto frameworks to estimate digestible carbohydrate content.
- Is sugar listed separately from carbs on a label?
- Yes, but sugar is a subset of total carbohydrates, not a separate addition. The label shows Total Carbohydrates as the main number, with Sugars indented beneath it as a component. Add the two together and you will count the same sugar twice.
- How do I calculate net carbs from a label?
- Subtract the Dietary Fiber grams from the Total Carbohydrates grams. Some people also subtract sugar alcohols, depending on the type. For example: 20g total carbs minus 5g fiber equals 15g net carbs. This is a practical estimate, not an officially regulated calculation.