Net carbs are total carbohydrates minus fiber minus most sugar alcohols. This is the metric that matters for keto, low-carb eating, and my Bone Broth Diet framework because it reflects the carbohydrates that actually affect blood sugar and insulin. Fiber passes through the digestive system without being absorbed as glucose, and most sugar alcohols are also poorly absorbed, so subtracting these from total carbohydrates gives a more accurate picture of how a food will affect your blood sugar and metabolic state.
For anyone new to low-carb eating, understanding net carbs is essential because food labels typically show total carbohydrates rather than net carbs. Reading a label and doing the quick subtraction (total carbs minus fiber) gives you the number you actually need. Let me walk you through how net carbs work, how to calculate them accurately, and why the distinction matters for your daily eating.
The Basic Formula
Net carbs = Total carbohydrates minus fiber minus sugar alcohols (in most cases).
Example: a food with 20 grams of total carbs, 8 grams of fiber, and 4 grams of erythritol contains 8 grams of net carbs (20 minus 8 minus 4). This is the number that counts toward your daily carb budget on keto or low-carb eating.
Why Fiber Doesn’t Count
Fiber is a category of carbohydrate that the human digestive system cannot break down into glucose. Soluble fiber can be fermented by gut bacteria (producing short-chain fatty acids that support gut health), but it does not contribute to blood glucose or insulin response. Insoluble fiber passes through the digestive system essentially unchanged.
Because fiber does not raise blood sugar, subtracting it from total carbs gives a more useful number for anyone tracking carbohydrate intake for metabolic reasons. A cup of raspberries contains around 15 grams of total carbs but 8 grams of fiber, meaning only 7 grams of net carbs. This is meaningfully different from a food with 15 grams of total carbs and no fiber (like a slice of white bread), which would deliver the full 15 grams as glucose to your bloodstream.
The Sugar Alcohol Question
Sugar alcohols (erythritol, xylitol, sorbitol, mannitol, and others ending in -ol) are poorly absorbed by the human digestive system and have minimal effect on blood glucose for most people. Erythritol in particular is largely excreted unchanged and does not raise blood sugar or insulin. This is why erythritol is the sugar alcohol most commonly used in keto baking and commercial low-carb products.
The nuance is that individual response varies. Some people (particularly those with sensitive digestion) do experience some blood sugar response to sugar alcohols, and higher doses can cause digestive discomfort. For most people following keto, subtracting erythritol from total carbs produces an accurate net carb count. For xylitol and other sugar alcohols, subtracting only half the grams is a more conservative approach that some practitioners recommend.
Reading Labels for Net Carbs
US food labels show total carbohydrates and total fiber but do not always break out sugar alcohols separately. Some low-carb products include a net carbs line on the label; others require you to do the math. The Harvard T.H. Chan School of Public Health Nutrition Source has covered dietary carbohydrate quality in the broader context of nutrition labeling.
When a product does not show sugar alcohols separately, look at the ingredient list. If erythritol, xylitol, or another sugar alcohol appears in the ingredients but is not broken out in the nutrition facts, you can generally assume the total carbohydrate figure includes it. Reading the ingredient panel alongside the nutrition facts gives you the full picture.
Net Carb Ranges for Different Approaches
Strict ketogenic: 20 to 30 grams of net carbs per day. This range keeps most people in nutritional ketosis, the metabolic state where the body burns fat for fuel and produces ketones. Achieving and maintaining ketosis requires strict adherence to this narrow range.
Moderate low-carb: 50 to 100 grams of net carbs per day. This range supports weight loss and metabolic health for most women without requiring the strict adherence of ketosis. My Bone Broth Diet framework operates within this range.
Liberal low-carb: 100 to 150 grams of net carbs per day. This range supports maintenance and moderate metabolic benefits while allowing more variety in eating including moderate portions of whole-food starches like sweet potatoes, winter squash, and berries.
Standard American diet: 250 to 400 grams of net carbs per day. This range reflects typical unstructured eating with substantial refined grains, added sugars, and processed foods, and produces the metabolic patterns (insulin resistance, weight gain, inflammation) that low-carb approaches are designed to reverse.
Net Carbs in Common Foods
Non-starchy vegetables tend to be very low in net carbs. A cup of raw spinach contains 0.5 grams net carbs. A cup of raw kale contains 5 grams total carbs and 3 grams fiber (2 grams net). Broccoli, cauliflower, zucchini, bell peppers, and cucumber all fall in the 3 to 8 gram net carb range per cup.
Berries are the lowest-carb fruits. A cup of raspberries: 7 grams net. A cup of blackberries: 6 grams net. A cup of strawberries: 8 grams net. A cup of blueberries: 17 grams net (higher than the other berries).
Nuts vary meaningfully. One ounce of macadamia nuts: 1.5 grams net. One ounce of pecans: 1.2 grams net. One ounce of almonds: 2.5 grams net. One ounce of cashews: 8 grams net (much higher than the tree nuts).
Where Bone Broth Fits
Bone broth is essentially carb-free (typically 0 to 1 gram of net carbs per cup depending on the brand and any added vegetables during simmering), making it fully compatible with any low-carb or ketogenic approach. My Bone Broth Classic Chicken contains negligible net carbs while delivering roughly 9 grams of collagen-derived protein per cup. Daily bone broth practice fits into any carb budget without competing for the modest carb allocation that keto or low-carb eating provides.
The Practical Application
Understanding net carbs lets you make food choices based on how foods actually affect your metabolism rather than on total carbohydrate figures that overstate the impact of fiber-rich whole foods. This matters practically because a cup of raspberries (7 grams net) is a fundamentally different food than a cup of orange juice (26 grams net), even though both are marketed as fruit. Tracking net carbs rather than total carbs gives you a more accurate picture of your daily metabolic reality and helps you build the eating pattern that supports your goals. The full Bone Broth collection supports daily low-carb practice by delivering meaningful nutrition without competing for the carb budget.
Frequently Asked Questions
What are net carbs?
Net carbs are total carbohydrates minus fiber minus most sugar alcohols. This calculation reflects the carbohydrates that actually raise blood sugar and insulin, since fiber and most sugar alcohols pass through the digestive system without being absorbed as glucose. Net carbs are the metric that matters for keto, low-carb eating, and blood sugar management.
How do you calculate net carbs?
Subtract grams of fiber and grams of sugar alcohols (particularly erythritol) from total grams of carbohydrates. Example: a food with 20 grams total carbs, 8 grams fiber, and 4 grams erythritol contains 8 grams of net carbs. For xylitol and other less-inert sugar alcohols, some practitioners subtract only half the grams as a conservative approach.
How many net carbs on keto?
Strict ketogenic eating targets 20 to 30 grams of net carbs per day to maintain nutritional ketosis. Moderate low-carb approaches allow 50 to 100 grams of net carbs per day and support weight loss and metabolic health without strict ketosis. My Bone Broth Diet operates in the moderate low-carb range. Standard American diet typically contains 250 to 400 grams of net carbs per day.
Are net carbs or total carbs more important?
Net carbs are more relevant for metabolic outcomes because they reflect the carbohydrates that actually affect blood sugar and insulin. Total carbs overstate the metabolic impact of fiber-rich whole foods like berries, vegetables, and nuts. For keto, low-carb eating, and blood sugar management, net carbs are the more useful metric. For general dietary tracking without specific low-carb goals, total carbs may be sufficient.
