What Are Net Carbs? How to Count Them on Keto
Net carbs are the carbohydrates your body actually digests and turns into glucose: total carbohydrate minus fibre and minus most sugar alcohols. On keto, net carbs — not total carbs — are the number you track against your daily target, because fibre and many sugar alcohols have little to no effect on blood sugar or ketosis.
The net carb formula
Net carbs = total carbohydrate − dietary fibre − sugar alcohols (where applicable). Fibre passes through largely undigested, so it doesn't raise blood glucose. Sugar alcohols such as erythritol have a negligible glycaemic impact and are usually subtracted in full.
For example, an avocado with 12g total carbs and 9g fibre contains just 3g net carbs — which is why it's a keto staple despite the carb count on the label looking high.
When not to subtract everything
Not all sugar alcohols are equal. Erythritol can be subtracted in full, but maltitol raises blood sugar significantly — count roughly half of it as net carbs.
Outside the US, nutrition labels in the UK and EU already list 'carbohydrate' as the digestible amount and show fibre separately, so you typically don't subtract fibre again. Always read the label format before doing the maths.
Why net carbs matter on keto
Ketosis depends on keeping digestible carbohydrate low — usually around 20–30g net carbs a day in the keto phase. Tracking net carbs lets you eat fibre-rich, nutrient-dense whole foods like leafy greens, nuts and avocado without blowing your target.
Keto Club logs net carbs automatically for every food and meal, and shows your running total against the target for the phase you're in, so you never have to do the subtraction by hand.
Frequently asked
Should I count net carbs or total carbs on keto?
Most people count net carbs, because fibre and erythritol have little effect on blood sugar or ketosis. If you're not seeing results, try tracking total carbs for a stricter approach.
Do I subtract fibre from UK food labels?
Usually not. UK and EU labels list digestible 'carbohydrate' with fibre shown separately, so the carbohydrate figure is already close to net carbs. US labels include fibre in total carbs, so you subtract it there.