What Are Net Carbs? How to Calculate Them
Most low-carb plans track net carbs rather than total carbs. The difference can be substantial, and calculating it incorrectly can stall progress or cause you to restrict unnecessarily.
Total carbs vs net carbs
Total carbohydrates on a nutrition label includes starches, sugars, fibre and sugar alcohols. Dietary fibre passes through the gut largely undigested without raising blood glucose. Net carbs represent only the carbohydrates that the body actually absorbs and processes as glucose.
The formula
Net carbs = Total Carbohydrate (g) minus Dietary Fibre (g). For foods containing sugar alcohols, some low-carb frameworks subtract those too, though the calculation varies by alcohol type.
Sugar alcohols: to subtract or not
- Erythritol: almost fully excreted, has minimal blood sugar impact. Most frameworks subtract it entirely.
- Xylitol and sorbitol: partially absorbed. Usually subtracted at half value, or not at all in stricter protocols.
- Maltitol: absorbed more like regular sugar. Generally not subtracted.
- When in doubt, count sugar alcohols in full and adjust from there.
Reading a nutrition label for net carbs
Find the Total Carbohydrate line. Below it, Dietary Fibre is listed as a sub-item. Subtract the fibre from the total. If sugar alcohols are listed (often labelled Sugar Alcohols, Polyols or by the specific name), decide whether to subtract based on the type.
Does this apply to everyone?
People managing blood glucose for diabetes or on certain medications should not adjust carb targets without medical input. Net carb tracking is a useful tool for low-carb diets in generally healthy people. If you have diabetes or take medication that affects blood sugar, involve your doctor before changing how you count carbohydrates.
The No Carbs Challenge app helps track your daily intake. For a broader look at what to eat on a low-carb diet, see what to eat instead of carbs.
Common questions
- What are net carbs on a nutrition label?
- Net carbs are the total carbohydrate content minus dietary fibre. Fibre does not raise blood sugar, so low-carb frameworks subtract it. Net carbs = Total Carbohydrate minus Dietary Fibre.
- Do sugar alcohols count as net carbs?
- It depends on the type. Erythritol has minimal blood sugar impact and is typically subtracted fully. Maltitol is absorbed significantly and is usually counted in full. Xylitol and sorbitol are often subtracted at half value.
- How many net carbs per day for low carb?
- Typical low-carb targets are 50 to 100 g net carbs per day. Strict ketogenic diets usually target under 20 to 30 g. Anyone with diabetes or on blood-glucose medication should set targets with a doctor.