# Net Carbs Explained: How to Count Carbs on Keto

Source: https://theketovibe.com/learn/net-carbs-explained · The Keto Vibe · Updated 2026-10-25

> What net carbs are, how to calculate them from a nutrition label, which sugar alcohols count, and why US and EU labels need different math.

## Key takeaways

- Net carbs = total carbohydrates − fiber. It’s the number most keto eaters track.
- On US and Canadian labels, subtract fiber. On EU, UK and Australian labels, “carbohydrate” already excludes fiber, so don’t subtract it again.
- Erythritol and allulose can be subtracted in full; maltitol raises blood sugar and should be mostly counted.
- About 20 g of net carbs a day is the classic keto starting point.

Every recipe on The Keto Vibe lists **net carbs** per serving. It’s the number most keto eaters track, and it’s easy to get wrong when you read a nutrition label. Here’s how it works, and where people slip up.

## What are net carbs?

Net carbs are the carbohydrates your body digests and turns into glucose. Fiber is a carbohydrate too, but it passes through mostly undigested, so it’s subtracted:

> **Net carbs = total carbohydrates − fiber**

That’s why an avocado, with around 8.5 g of total carbs per 100 g, counts as under 2 g net: most of its carbohydrate is fiber.

## A worked example

A serving of a low-carb tortilla lists:

| Label line | Amount |
| --- | --- |
| Total carbohydrate | 12 g |
| Dietary fiber | 9 g |

Net carbs: 12 − 9 = **3 g**.

## US labels vs. EU and UK labels

This is where most counting mistakes happen.

- **US and Canada:** “Total carbohydrate” *includes* fiber. Subtract the fiber line to get net carbs.
- **EU, UK and Australia:** “Carbohydrate” *already excludes* fiber. That number is close to net carbs as it is. Subtracting fiber again would undercount.

> **The double-subtraction trap:** If you buy a UK chocolate bar labelled 15 g carbohydrate and 10 g fiber, the net carbs are about 15 g, not 5 g. Subtracting fiber from an EU or UK label is the most common way people accidentally eat more carbs than they think.

## Sugar alcohols: which ones count

Sugar alcohols (polyols) sweeten many “keto” products. They are partly absorbed, and some raise blood sugar more than others:

| Sweetener | How to count it | Why |
| --- | --- | --- |
| Erythritol | Subtract in full | Mostly absorbed and passed out in urine unchanged |
| Allulose | Subtract in full | A rare sugar the body barely metabolizes |
| Xylitol | Count about half | Partly absorbed; mild effect on blood sugar |
| Sorbitol | Count about half | Partly absorbed; can upset digestion |
| Maltitol | Count almost all | Raises blood sugar noticeably |

So a bar with 20 g total carbs, 8 g fiber and 10 g erythritol has about 2 g net carbs. Swap the erythritol for maltitol and it’s closer to 10 g. Lesson 5 compares [keto sweeteners](https://theketovibe.com/learn/keto-sweeteners) in depth.

## How many net carbs on keto?

A common starting point is about **20 g of net carbs a day**, which is roughly where most people reach ketosis. Some people stay in ketosis at higher intakes, especially if they’re very active. Everyone is different, and if you have a medical condition, check with your doctor before changing your diet.

To set your own fat and protein targets around that carb limit, try our [keto macro calculator](https://theketovibe.com/tools/macro-calculator). Once your targets are saved, every recipe on this site shows how much of your daily carb budget it uses.

## Where net carbs hide

- **Sauces and dressings:** ketchup, barbecue sauce and sweet chili sauce are mostly sugar.
- **“Low-fat” products:** fat is often replaced with sugar or starch.
- **Vegetables vary a lot:** leafy greens, zucchini and cauliflower are very low; carrots, peas and corn add up quickly.
- **Nuts:** pecans and macadamias are low, cashews and pistachios are much higher.
- **Milk:** a cup of whole milk has around 12 g of net carbs from lactose. Cream has a fraction of that.

Curious how your instincts compare? Play [Higher or Lower](https://theketovibe.com/tools/higher-or-lower), or look anything up in the [keto food list](https://theketovibe.com/learn/keto-food-list).

## FAQ

**How do you calculate net carbs?**

Take total carbohydrates and subtract dietary fiber. If the food contains erythritol or allulose, subtract those too. On EU and UK labels, the carbohydrate figure already excludes fiber, so use it as it is.

**Should I count total carbs or net carbs on keto?**

Most people count net carbs, because fiber isn’t digested into glucose. Some people prefer total carbs for a stricter approach, often around 20 to 30 g of total carbs a day.

**Do sugar alcohols count as carbs?**

It depends on the sugar alcohol. Erythritol is barely absorbed and is usually subtracted in full. Xylitol is often counted at about half. Maltitol raises blood sugar noticeably and is best counted almost fully.