Net Carb Calculator
Net carbs are the only carbs that count on keto. Enter the figures from any nutrition label to find the number that matters.
Read these straight off the nutrition label. In the UK, the carbohydrate figure already excludes fibre — see the note below if your label follows UK rules.
Net carbs
7g
Staying under 20g net carbs a day?
The free 5-Day Keto Kickstart does the counting for you — every meal comes with its net-carb count, plus a shopping list and fasting schedule.
Why net carbs, not total carbs
Carbohydrate on a label is a single number, but your body treats its parts very differently. Fibre passes through largely undigested — it doesn't raise blood sugar or spike insulin, so it doesn't pull you out of ketosis. Sugar alcohols (erythritol, xylitol and friends) are only partly absorbed, so they count for less than ordinary sugar.
That's why a high-fibre avocado or a handful of leafy greens barely dents your daily budget, while a single slice of bread can use it all up. Tracking net carbs lets you eat more real food while staying in ketosis — and it's the number Keto Club logs for you automatically.
Net carbs — your questions answered
What are net carbs?
Net carbs are the carbohydrates your body actually digests and that raise your blood sugar. You calculate them by taking total carbohydrate and subtracting fibre and half of any sugar alcohols. On keto, net carbs — not total carbs — are the number you track against your daily limit.
How do you calculate net carbs?
Net carbs = total carbohydrate − fibre − (sugar alcohols ÷ 2). Fibre passes through largely undigested, so it's subtracted in full. Most sugar alcohols are only partly absorbed, so a common rule of thumb subtracts half. The result is clamped at zero — net carbs can't be negative.
Why subtract only half of sugar alcohols?
Sugar alcohols vary in how much they affect blood sugar. Erythritol has almost no impact and could arguably be subtracted in full, while maltitol raises blood sugar quite a bit and should barely be subtracted at all. Halving is a safe middle-ground default. If a product lists erythritol specifically, you can subtract it fully; treat maltitol as a near-full carb.
Do UK and US labels count carbs differently?
Yes. In the US and Canada, the 'Total Carbohydrate' figure includes fibre, so you subtract fibre to get net carbs. In the UK and EU, the 'Carbohydrate' figure already excludes fibre (fibre is listed separately), so that number is effectively net carbs already. If your label follows UK rules, enter 0 for fibre, or simply read the carbohydrate value as your net carbs.
How many net carbs can I have on keto?
Most people enter and stay in ketosis at 20–30g of net carbs per day, with 20g being a reliable target for beginners. Once you're fat-adapted you may be able to raise this, especially around training — that's the idea behind keto-cycling, where you phase your carb intake on purpose rather than staying at a hard floor forever.
Should I count net carbs or total carbs?
For ketogenic and low-carb diets, net carbs are the more useful number because fibre and most sugar alcohols don't raise blood sugar. Some stricter protocols and most diabetes guidance prefer total carbs to be cautious. If you're not losing weight on net carbs, try counting total carbs for a fortnight and compare.
Stop doing the maths by hand
Keto Club counts net carbs for every food you log and warns you before you go over.