At a glance
Net carbs are the carbohydrates most likely to affect blood sugar and are commonly tracked by people following low-carb and ketogenic diets. Unlike total carbohydrates, net carbs account for dietary fiber and, in some cases, certain sugar alcohols that have little effect on blood glucose.
Carbohydrates are one of the body's primary sources of energy, but not all carbohydrates are processed the same way.
While nutrition labels list total carbohydrates, many people following a low-carb or ketogenic diet focus on net carbs instead.
Discover what net carbs are, how they differ from total carbs, why they matter, and how to calculate them accurately.
What Are Net Carbs?
Net carbs are the carbohydrates remaining after subtracting dietary fiber—and, in some cases, certain sugar alcohols—from the total carbohydrates listed on a nutrition label.
The most common formula is:
Net Carbs = Total Carbohydrates − Dietary Fiber
For example, if a food contains:
- Total carbohydrates: 15 g
- Dietary fiber: 8 g
Its net carb count would be 7 grams.
This calculation is commonly used by people following low-carb or ketogenic eating patterns because fiber generally has less direct impact on blood sugar than digestible carbohydrates, although the effect can vary by fiber type and individual response.
It's important to know that “net carbs” isn’t an FDA-defined term. The U.S. Food and Drug Administration (FDA) requires manufacturers to list total carbohydrates on Nutrition Facts labels, so net carbs typically need to be calculated separately. As a result, you'll often need to calculate net carbs yourself or use a trusted tracking app (like Carb Manager!) that does it automatically.
Net Carbs vs. Total Carbs
Total carbs include carbohydrates in a food, including sugars, starches, dietary fiber, and sugar alcohols when present. This is the number listed on Nutrition Facts labels.
Net carbs are calculated by subtracting dietary fiber and, in some cases, certain sugar alcohols from total carbohydrates. This number is commonly used by people following low-carb or ketogenic diets because it estimates the carbohydrates more likely to be digested and absorbed.
For example, a food with 15 grams of total carbohydrates and 8 grams of fiber has 7 grams of net carbs.
Both numbers can be useful. Total carbs show the full carbohydrate content of a food, while net carbs can help with carb counting when fiber-rich foods are part of your eating plan. This is especially relevant for foods such as vegetables, nuts, seeds, and certain low-carb packaged products.
Why Do Net Carbs Matter?
Net carbs matter because many low-carb and ketogenic diets set daily carbohydrate targets. Tracking net carbs can make those targets easier to apply in real life, especially when meals include fiber-rich foods such as non-starchy vegetables, avocados, nuts, and seeds.
Total carbohydrates include fiber, even though fiber isn’t digested and absorbed the same way as sugar and starch. Because of this, counting total carbs alone may make some whole foods appear higher in carbohydrates than they are from a digestible-carb perspective.
For people following a ketogenic diet, net carbs are often used to estimate the carbohydrates most likely to affect ketosis. For those following a general low-carb diet, net carbs can help guide food choices while still leaving room for nutrient-dense, fiber-containing foods.
A meta-analysis published in Nutrients found that low-carbohydrate diets were associated with improvements in body weight, triglycerides, and HDL cholesterol compared with low-fat diets.
Net carbs don’t determine whether a food is healthy. They’re a tracking tool that can help you understand how different foods fit within your carbohydrate goals. Nutrient density, protein, healthy fats, vitamins, and minerals remain important parts of an overall healthy eating pattern.
How to Calculate Net Carbs
Calculating net carbs is straightforward once you understand what to look for on a Nutrition Facts label. In most cases, you can determine a food’s net carb content using total carbohydrates, dietary fiber, and, when applicable, certain sugar alcohols.
Net Carbs = Total Carbohydrates − Dietary Fiber
Some people also subtract certain sugar alcohols, depending on the type and their dietary approach.
1. Find the total carbohydrates
Start by locating the Total Carbohydrate line on the Nutrition Facts label. This number includes carbohydrates in the food, including sugars, starches, dietary fiber, and sugar alcohols when present.
2. Subtract dietary fiber
Because dietary fiber isn’t fully digested and absorbed, it’s generally subtracted from total carbohydrates when calculating net carbs.
For example, if a food contains:
- Total carbohydrates: 20 grams
- Dietary fiber: 8 grams
The food contains 12 grams of net carbs.
3. Check for sugar alcohols
Some foods marketed as low-carb or keto contain sugar alcohols as sweeteners. Certain sugar alcohols, such as erythritol, have minimal impact on blood sugar and are commonly subtracted when calculating net carbs. Others, including maltitol, are more readily absorbed and may contribute more digestible carbohydrates, so they shouldn’t automatically be treated the same.
4. Pay attention to serving size
The Nutrition Facts label reflects a single serving, not necessarily the entire package. If you eat more than one serving, calculate net carbs based on the amount you actually consume.
Foods Naturally Low in Net Carbs
Many whole foods are naturally low in net carbs, making them staples in low-carb and ketogenic eating patterns. Building meals around these foods can help you stay within your carbohydrate target while providing protein, healthy fats, fiber, vitamins, and minerals.
Here are some foods that are naturally low in net carbs:
1. Non-starchy vegetables
Leafy greens and other non-starchy vegetables are among the best sources of fiber while remaining relatively low in net carbs. Spinach, broccoli, cauliflower, zucchini, asparagus, bell peppers, and leafy greens can add volume, nutrients, and variety to meals without contributing large amounts of digestible carbohydrates.
2. Protein-rich foods
Fresh meat, poultry, fish, seafood, and eggs contain little to no carbohydrates, making them naturally low in net carbs. They're also excellent sources of protein, which supports muscle maintenance and can help promote fullness.
3. Healthy fats
Foods such as avocados, olives, olive oil, avocado oil, butter, and other minimally processed fats contain few or no net carbs and are commonly included in low-carb and ketogenic diets.
4. Dairy
Many cheeses are naturally low in net carbs, while foods such as plain full-fat Greek yogurt and full-fat cottage cheese can also fit into a low-carb eating pattern when consumed in appropriate portions. Because carbohydrate content varies by product, it's always a good idea to check the Nutrition Facts label.
6. Nuts and seeds
Pecans, walnuts, macadamia nuts, chia seeds, flaxseeds, and other nuts and seeds can provide healthy fats, fiber, and important nutrients while remaining relatively low in net carbs. Portion size still matters, as the carbohydrate content can add up when eaten in large amounts.
Choosing mostly whole, minimally processed foods can make it easier to manage your net carb intake while supporting an overall nutrient-dense eating pattern.
Common Mistakes When Counting Net Carbs
Counting net carbs becomes easier with practice, but a few common mistakes can lead to inaccurate tracking. Understanding what to watch for can help you make more informed food choices and stay closer to your carbohydrate goals.
Here are 5 common mistakes to look out for when counting net carbs.
1. Ignoring serving sizes
Nutrition Facts labels are based on a single serving, not necessarily the entire package. If you eat more than one serving, you'll need to calculate the net carbs based on the total amount you consume.
2. Treating all sugar alcohols the same
Not all sugar alcohols have the same effect on blood sugar. While some, such as erythritol, have little impact, others, including maltitol, are partially absorbed and can contribute more digestible carbohydrates. Check the ingredient list instead of assuming all sugar alcohols can be subtracted.
3. Relying on front-of-package claims
Labels such as "keto-friendly" or "low carb" can be helpful, but they don't always tell the full story. Reading the Nutrition Facts label and ingredient list can give you a more accurate understanding of a food's carbohydrate content.
4. Overlooking condiments and beverages
Sauces, salad dressings, flavored coffee drinks, and other beverages can contribute more carbohydrates than expected. These small additions can add up throughout the day if they aren't accounted for.
5. Estimating portion sizes
It's easy to underestimate how much you're eating, especially with foods like nuts, seeds, cheese, and packaged snacks. Measuring portions or using a nutrition tracking app can improve accuracy and help you better understand your daily carbohydrate intake.
How Carb Manager Makes Tracking Net Carbs Easier
Calculating net carbs by hand can work well, but it becomes more challenging when you're tracking multiple meals, recipes, or restaurant foods throughout the day.
Carb Manager automatically calculates net carbs from nutrition information, helping you spend less time doing the math yourself. You can scan barcodes, search a verified food database, log homemade recipes, and track restaurant meals in one place.
The app also lets you monitor your daily net carb intake alongside calories, protein, fat, and other nutrients, making it easier to stay aligned with your nutrition goals.
Whether you're following a ketogenic diet or simply reducing your carbohydrate intake, Carb Manager can help simplify the tracking process.
Key Takeaways
- Net carbs are calculated by subtracting dietary fiber—and, in some cases, certain sugar alcohols—from total carbohydrates.
- Many people following low-carb or ketogenic diets track net carbs to help stay within their daily carbohydrate target.
- Reading Nutrition Facts labels, paying attention to serving sizes, and understanding sugar alcohols can help you calculate net carbs more accurately.
- Whole foods such as non-starchy vegetables, protein-rich foods, healthy fats, and many nuts and seeds are naturally low in net carbs.
- Carb Manager makes it easy to calculate, track, and monitor your net carb intake throughout the day.
FAQs
1. What are net carbs?
Net carbs are the carbohydrates remaining after subtracting dietary fiber—and, in some cases, certain sugar alcohols—from the total carbohydrates listed on a Nutrition Facts label. Many people following low-carb or ketogenic diets use net carbs to estimate the carbohydrates most likely to affect blood sugar.
2. How do you calculate net carbs?
The basic formula is:
Net Carbs = Total Carbohydrates − Dietary Fiber
If a food contains sugar alcohols, some people also subtract certain types that have little effect on blood sugar. Because sugar alcohols vary in how they're digested and absorbed, they shouldn't all be treated the same.
3. Are net carbs the same as total carbs?
No. Total carbohydrates include carbohydrates in a food, including sugars, starches, dietary fiber, and sugar alcohols when present. Net carbs estimate the carbohydrates that are more likely to be digested and absorbed.
4. Why do people count net carbs instead of total carbs?
Many people following low-carb or ketogenic diets count net carbs because dietary fiber isn't fully digested and absorbed like other carbohydrates. Tracking net carbs can make it easier to include fiber-rich foods while staying within a daily carbohydrate target.
5. Do all sugar alcohols count toward net carbs?
No. Sugar alcohols vary in how they're digested and absorbed, so they don't all have the same effect on blood sugar. Some, such as erythritol, have little effect, while others, including maltitol, may contribute more digestible carbohydrates.
6. What foods are naturally low in net carbs?
Many whole foods are naturally low in net carbs, including non-starchy vegetables, meat, poultry, fish, eggs, avocados, olive oil, cheese, and many nuts and seeds.
7. Are net carbs only important on a keto diet?
No. While net carbs are commonly tracked on ketogenic diets, many people following a general low-carb eating pattern also use them to help manage their carbohydrate intake.
8. Does Carb Manager calculate net carbs automatically?
Yes. Carb Manager automatically calculates net carbs from nutrition information, making it easier to track meals, recipes, and restaurant foods without doing the math yourself.
