Calculate your ideal ketogenic diet macros — fat, protein, and net carbs — based on your TDEE, activity level, and body composition goals.
The ketogenic diet shifts your body's primary fuel source from glucose to ketone bodies derived from fat. To achieve and maintain nutritional ketosis, your macronutrient ratios must be carefully controlled — typically 70–75% of calories from fat, 20–25% from protein, and just 5–10% from net carbohydrates (usually 20–50g/day).
This calculator generates personalized keto macros based on your Total Daily Energy Expenditure (TDEE), body composition, and goal (maintenance, weight loss, or therapeutic ketosis). It calculates grams of fat, protein, and net carbs rather than just percentages, because hitting the absolute gram targets is what actually determines whether you stay in ketosis.
Whether you're starting keto for the first time or fine-tuning your macros for better results, this tool provides the specific numbers you need to stay in your target ketone range while meeting your nutritional needs. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation.
Keto requires more precise macro tracking than most diets because even small increases in carb intake can knock you out of ketosis. Generic macro calculators don't account for the unique requirements of ketosis maintenance. This calculator sets protein high enough to preserve muscle, limits net carbs to induce ketosis, and fills the remaining calories with fat — in that priority order.
TDEE (Mifflin-St Jeor): • Male: 10×weight(kg) + 6.25×height(cm) − 5×age − 5 • Female: 10×weight(kg) + 6.25×height(cm) − 5×age − 161 TDEE = BMR × Activity Factor Keto Macros: • Net Carbs (g) = (TDEE × carb%) / 4 • Protein (g) = (TDEE × protein%) / 4 • Fat (g) = (TDEE × fat%) / 9 Standard Keto: 75% fat / 20% protein / 5% carbs Moderate Keto: 65% fat / 25% protein / 10% carbs High-Protein Keto: 60% fat / 35% protein / 5% carbs
Result: 145g fat / 100g protein / 25g net carbs (1,800 kcal)
BMR = 10(85) + 6.25(178) − 5(35) − 5 = 1,788 kcal. TDEE at 1.55 activity = 2,771 kcal. A moderate 20% deficit gives 2,217 kcal, rounded to ~2,000 for simplicity. At 75/20/5: Fat = 2000×0.75/9 = 167g, Protein = 2000×0.20/4 = 100g, Net Carbs = 2000×0.05/4 = 25g. Total fat calories: 1,500; protein: 400; carbs: 100. This keeps carbs well under the 50g ketosis threshold.
When carbohydrate intake drops below approximately 50g/day, liver glycogen depletes within 24–48 hours. The liver then begins converting fatty acids into ketone bodies (beta-hydroxybutyrate, acetoacetate, and acetone) as an alternative fuel source for the brain and tissues that cannot efficiently use fatty acids directly. This metabolic state — nutritional ketosis — is characterized by blood ketone levels of 0.5–3.0 mmol/L.
Contrary to popular belief, keto macros should be set in this priority: (1) Set protein first, based on lean mass and activity level, typically 1.6–2.2 g/kg. (2) Set net carbs at your ketosis threshold, usually 20–50g. (3) Fill remaining calories with fat. This approach ensures muscle preservation and ketosis maintenance, using fat as the flexible variable.
The most frequent mistakes include: not tracking net carbs accurately (hidden carbs in sauces, condiments, and processed foods); under-eating protein out of fear of gluconeogenesis; neglecting electrolytes (causing "keto flu" that's actually preventable); and either eating too much fat (stalling weight loss) or too little fat (feeling miserable). A food scale and tracking app are essential tools, especially in the first month.
Beyond standard keto (SKD), there are several adapted protocols: Targeted Keto (TKD) adds 15–50g carbs around workouts for athletes; Cyclical Keto (CKD) alternates 5–6 keto days with 1–2 carb-loading days for high-intensity athletes; and Modified Atkins-style keto allows slightly more protein and carbs while still maintaining ketosis. Choose the variant that best fits your activity level and sustainability.
Most people can maintain ketosis at 20–50g net carbs per day. The threshold varies by individual — more active people and those with more muscle mass can typically tolerate slightly higher amounts. Starting at 20g net carbs and gradually testing upward is the safest approach to find your personal limit.
This is a common myth. Gluconeogenesis (the conversion of protein to glucose) is demand-driven, not supply-driven. Eating more protein does not automatically increase glucose production. Research consistently shows that adequate protein (1.6–2.2 g/kg) does not impair ketosis in healthy individuals. Prioritize protein for muscle maintenance.
Standard keto (SKD) allocates 75% of calories to fat, 20% to protein, and 5% to carbs. High-protein keto increases protein to 35% and reduces fat to 60%, keeping carbs at 5%. High-protein keto is better for athletes and people doing resistance training who need more protein for muscle recovery and growth.
Most people enter ketosis within 2–4 days of limiting net carbs to 20–50g/day. Full fat-adaptation (where your body efficiently uses fat and ketones for fuel) takes 2–6 weeks. During the transition, you may experience "keto flu" symptoms — fatigue, headaches, and irritability — which are usually caused by electrolyte depletion.
No. On keto, fat is used to provide satiety and energy, but if your goal is fat loss, you want your body to burn its own stored fat. This means eating enough fat to feel satisfied but not stuffed. Creating a calorie deficit (15–25% below TDEE) is still necessary for weight loss on keto — the high-fat aspect simply makes the deficit more sustainable.
When you restrict carbs, your kidneys excrete more sodium, which also causes potassium and magnesium loss. Aim for 5–7g sodium (salt your food liberally), 3–4g potassium (avocado, leafy greens, lite salt), and 400–600mg magnesium (supplements or nuts). Proper electrolyte balance prevents headaches, cramps, fatigue, and heart palpitations.
Yes, but high-intensity and explosive activities (sprinting, heavy lifting) may be slightly impaired during the first 2–4 weeks of fat adaptation. Endurance performance often improves on keto. Some athletes use a targeted keto diet (TKD), consuming 15–50g fast-acting carbs 30 minutes before intense workouts to fuel glycolytic activity without disrupting ketosis.
For most healthy people, well-formulated keto diets with adequate micronutrient intake appear safe for 1–2+ years based on available research. Key considerations: ensure sufficient fiber from low-carb vegetables, vary your protein and fat sources, monitor blood lipids periodically, and consider cycling in maintenance periods. People with liver, kidney, or pancreatic conditions should consult their doctor first.