Calculate net carbohydrates for keto and low-carb diets. Subtract dietary fiber and sugar alcohols from total carbs to find your net carbs.
Total Carbs: 12 g, Dietary Fiber: 9 g, Sugar Alcohols (Erythritol): 2 g
Net Carbs: 12 − 9 − (2 × 100%) = 1 g
Erythritol is fully subtractable (factor = 0), leaving minimal net carbs. Excellent for keto!
Total Carbs: 23 g, Dietary Fiber: 9 g, Sugar Alcohols (Maltitol): 10 g
Net Carbs: 23 − 9 − (10 × 50%) = 23 − 9 − 5 = 9 g
Maltitol is only 50% subtractable. Despite 10 g of sugar alcohols, only 5 g are deducted, resulting in 9 net carbs.
Total Carbs: 18 g, Dietary Fiber: 4 g, Sugar Alcohols (Xylitol): 8 g
Net Carbs: 18 − 4 − (8 × 50%) = 18 − 4 − 4 = 10 g
Xylitol is 50% subtractable. Even with 8 g of xylitol, only 4 g are deducted from total carbs.
Net carbs are the carbohydrates that your body actually digests and absorbs, affecting blood sugar and insulin levels. They are calculated by subtracting dietary fiber and sugar alcohols from total carbohydrates.
On keto and low-carb diets, tracking net carbs rather than total carbs allows you to include more fiber-rich vegetables and sugar-alcohol-sweetened products without breaking ketosis. The concept is based on the understanding that fiber passes through the body undigested, and certain sugar alcohols have minimal impact on blood sugar.
Different sugar alcohols have different effects on blood sugar:
Eat plenty of non-starchy vegetables like spinach, broccoli, and cauliflower. Fiber subtracts from total carbs without the calories.
When using sugar alcohols, erythritol is the most keto-friendly option as it's fully subtractable and has zero glycemic impact.
Some products advertise "net carbs" but may subtract all sugar alcohols at 100%. Always calculate yourself using the nutrition facts.
Typical keto net carb limits are 20–50 g per day. Use this calculator to track your daily intake accurately.
Net carbs are the carbohydrates in food that are actually digested and absorbed by the body, impacting blood sugar and insulin levels. They are calculated by taking total carbohydrates and subtracting dietary fiber (which passes through the body undigested) and sugar alcohols (which have minimal impact on blood sugar).
The concept of net carbs is most commonly used in keto and low-carb diets, where the goal is to limit carbohydrate intake to maintain ketosis — a metabolic state where the body burns fat for fuel instead of glucose. By tracking net carbs instead of total carbs, dieters can include nutrient-dense, fiber-rich vegetables and sugar-alcohol-sweetened treats without exceeding their carb limits.
Many nutrition labels list total carbohydrates, which includes fiber and sugar alcohols that don't significantly affect blood sugar. By calculating net carbs, you get a more accurate picture of the carbs that will actually impact your ketosis and blood sugar levels. This is especially important for people managing diabetes, following a ketogenic diet, or anyone looking to reduce their effective carbohydrate intake.
Using our Net Carbs Calculator is simple and gives you accurate results in seconds:
Look at the nutrition facts panel on your food. Find Total Carbohydrates, Dietary Fiber, and Sugar Alcohols (if listed).
Input the grams for Total Carbs, Dietary Fiber, and Sugar Alcohols. Select the type of sugar alcohol used in the product.
Click "Calculate Net Carbs" and instantly see your net carbs, the intermediate values, and a full step-by-step breakdown.
Use the result to track your daily net carb intake. For keto, aim for 20–50 g of net carbs per day.
⚠️ Important Disclaimer: This Net Carbs Calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider or registered dietitian before starting any new diet, especially if you have diabetes, kidney disease, or other health conditions.